Is your company spending too much time on strategy development—with too little to show for it?
If you read nothing else on strategy, read these 10 articles (featuring “What Is Strategy?� by Michael E. Porter). We've combed through hundreds of Harvard Business Review articles and selected the most important ones to help you catalyze your organization's strategy development and execution.
HBR's 10 Must Reads on Strategy will inspire you
Distinguish your company from rivalsClarify what your company will and won't doCraft a vision for an uncertain futureCreate blue oceans of uncontested market spaceUse the Balanced Scorecard to measure your strategyCapture your strategy in a memorable phraseMake priorities explicitAllocate resources earlyClarify decision rights for faster decision making
This collection of best-selling articles featured article "What Is Strategy?" by Michael E. Porter, "The Five Competitive Forces That Shape Strategy," "Building Your Company's Vision," "Reinventing Your Business Model," "Blue Ocean Strategy," "The Secrets to Successful Strategy Execution," "Using the Balanced Scorecard as a Strategic Management System," "Transforming Corner-Office Strategy into Frontline Action," "Turning Great Strategy into Great Performance," and "Who Has the D? How Clear Decision Roles Enhance Organizational Performance."
Michael E. Porter is the leading authority on competitive strategy, the competitiveness and economic development of nations, states, and regions, and the application of competitive principles to social problems such as health care, the environment, and corporate responsibility.
Professor Porter is generally recognized as the "Father of Strategy", as has been identified in a variety of rankings and surveys as the world’s most influential thinker on management and competitiveness. He has ranked #1 on "Thinkers 50".
He is the Bishop William Lawrence University Professor, based at Harvard Business School. A University full-professorship is the highest professional recognition that can be awarded to a Harvard faculty member.
In 2001, Harvard Business School and Harvard University jointly created the Institute for Strategy and Competitiveness, dedicated to furthering Porter’s work.
Professor Porter is the author of 17 books and over 125 articles. He is the founder of elite strategy consulting firm, the Monitor Group.
He received a B.S.E. with high honors in aerospace and mechanical engineering from Princeton University in 1969, where he was elected to Phi Beta Kappa and Tau Beta Pi. He received an M.B.A. with high distinction in 1971 from the Harvard Business School, where he was a George F. Baker Scholar, and a Ph.D. in Business Economics from Harvard University in 1973.
A good set of articles for corporate strategy. 1. WHAT IS STRATEGY? - Operational Effectiveness is different from Strategy. The former, meaning to perform BETTER than rival with SIMILAR activities, is a need but still not sufficient enough. On the other hands, Strategy is an essential for every enterprise wanting to outstand from the crowd. Strategy is to perform different activities, or to perform same activities in different ways. - There are 3 sources of Strategy: customer-based (IKEA), access-based (Carmike Cinemas), variety-based (many choices) - A strategy must be persistent with time. Imitation can screw up business. - A strategy always has trade-offs. Straddling can't bring outperformance.
2. THE FIVE COMPETITIVE FORCES THAT SHAPE STRATEGY 5 Forces to Analyze an Industry - Threat of new entry, including supply side Economics of Scale, demand side benefit of scale, customer switching costs, capital requirement, incumbency advantages independence of size, unequal access to distribution channels, restrictive government policy. To counter this, increase costs of competing by investing deeply in R&D - Power of suppliers consists of concentrated industry, variable industries able to enjoy, switching costs in changing suppliers, differentiate products offered, no substitute, supplier joining the industry. To scare off this force, do specification for parts. - Power of buyers forced the business in case of only few buyers, products are standard, few switching costs among vendors, buyers join the industry. To limit the threat, provide better customer service. - Threat of substitutes occurs with attractive price performance, and when buyer’s cost of switching is low. One needs to have wider product choices to cope with this pressure. - Rivalry among existing competitors occurs when many competitors on stage with equal size and power, industry growth is slow, high exit barriers, leadership strength, and different approaches to compete with different goals which are blur to read. Company needs to have products with distinct value to neutralize this force. 3. BUILDING YOUR COMPANY’S VISION A vision includes 2 parts - Core ideology never dies. This consists of core values, regarding the passion; and core purpose, stating the reason for being. - Invisioned Future has a certain level of unreasonable confidence and commitment. Identify the Big, Hairy, Audacious Goals (BHAG) of the company: in 10-30 years, what can we become?. Then follow with a vivid description: how to become that? 4. REINVENTING YOUR BUSINESS MODEL A good business model has the following components: - Customer value proposition: solution to solve customers� problem that can stand out - Profit formula: to from price to deliver CVP. Identify revenue model, cost structure, margin model and resource velocity - Key resources - Key processes: including operational and managerial processes. Also include company’s rules, metrics and norms. 5. BLUE OCEAN STRATEGY - Red and blue oceans always co-exist! - Blue Ocean and Red Ocean are differentiated by costs. - Blue ocean business model is hard to copy, because it is easier to imagine than to do. 6. THE SECRETS TO SUCCESSFUL STRATEGY EXECUTION There are 4 areas an organization needs to ensure for high performance - Decision rights. Everyone knows the decisions and actions they are responsible for. This encourages high-level managers to reject operational decisions. - Information flows. Information needs to be clear from top to bottom, with speed. - Motivators. Once made, decisions must not be second-guessed. - Structure 7. USING BALANCED SCORECARD AS A STRATEGIC MANAGEMENT SYSTEM 4 processes from short term to long term objectives - Translating vision. Eg. “superior service to targeted customers� by identifying who they are and what constitutes superior service - Communicating and linking - Business planning with financial budget aligning with strategic goals - Feedback and learning 8. TRANSFORMING CORNER OFFICE STRATEGY INTO FRONLINE ACTION - An effective strategic principle forces trade-offs, tests, and sets clear boundaries within which employees operate and experiment - Mission is different from strategic principle. The former is aspirational statement, the latter call to action. - Creating and communicating strategic principle: o Draft a working SP by summarizing corporate strategy in a brief phrase o Test its endurance. Does it capture timeless essence? o Test its communicative power. Is the phrase clear, concise and memorable? Proud to say? o Test its ability to promote and guide action o Communicate it consistently, simply and repeatedly 9. TURNING GREAT STRATEGY INTO GREAT PERFORMANCE 7 rules to create strategy that delivers great performance - Keep simple, make concrete. Easily translated into action. Where the company is headed to and why? - Debate assumptions, not forecasts to reflect real market economics - Use rigorous framework, speak common language for all departments - Discuss resources deployments early. How long will it take to change something? - Clearly identify priorities. If I have only 1 hour to work, here’s what I’m going to focus on. - Continuously monitor performance - Reward and develop execution capabilities 10. WHO HAS THE D? RAPID decision model for different roles. - Recommend - Agree - Perform - Input - Decide
This is just an amazing set of articles around strategy. The first two from Michael Porter were tough ones, i could berely follow to a degree i was thinking to drop the book. I skipped the second article and moved on, and the rest of articels were amazing.. especially the ones related to vision, blue ocean strategy, execution, and the strategy principles. I would highly recommend this book for those with business backgound (either their own, or have been working for the past 5 years or so).
I don't know if this could be called a 'book' in all the extension of the word, but this is one of the most instructive books I've read in my life (although I haven't read that much).
It may be because before this book I barely know anything about strategy and corporate plans. Just as the subtitle says: "If you read nothing else, read this". Absolutely.
A few of the concepts that had stuck with me:
- A strategy must include tradeoffs, to be difficult to replicate. - The strategy is as much as what you won't do as much as you will do. - A company vision is composed of different parts, the core something that not changes ever and the envisioned future, both things must inspire action, not as the dull and boring enunciates we think of as the 'mission' and 'vision' of the companies. - To close the gap between a plan an the reality you need a set of actions and measures. But one of the most important actions and characteristics across high performing organizations is the ability to decide quickly and right. - You must communicate effectively your strategy and get buy-in from every level. - The vision of your company will help you hire the right people - You can craft a phrase that encapsulates the essence of your strategy to help people take action quickly
I've learned much more and I hope I can write to avoid forgetting and practice what I've learned soon.
a surprisingly useful read, re-read, and resource for anybody studying or working in strategy. this is what i imagine organic case prep to look like hahahah
my favorite articles are:
What Is Strategy? by Michael E. Porter The Five Competitive Forces That Shape Strategy by Michael E. Porter Blue Ocean Strategy by W. Chan Kim & Renée Mauborgne Who has the D? How Clear Decision Roles Enhance Organizational Performance by Paul Rogers and Marcia Blenko
Набор статей от именитых авторов, теоретиков, по бизнес стратегии. Часть идей типа BSC уже потеряла поклонников, часть актуальна. Скорее книга для студентов, чем для предпринимателей
If you are into managing organizations yearning to know what strategy actually means and how to devise it, then this is a book you wouldn’t ignore. It’s a compilation of articles published in HBR, not a real book in shape - each article got at least something to reflect.
"Operational efficiency is not strategy". I like the fact Michael Porter stresses on Strategy. He clarifies that bringing the same output with less resource is not strategy, but rather efficiency. Many organizations appear to have misconstrued this point, and in the making of strategy, they end up somewhere else, mostly ending up finding new techniques � not strategy.
According to Porter, the essence of strategy is choosing a unique and valuable position rooted in systems of activities that others can't match or replicate. So, it is something to do with innovation - I think if every organization strives to formulate the right strategy, the world would be a more innovative place than it is.
The other articles on blue ocean strategy and strategy execution are also equally good. At times, you may not fully agree with certain ideas presented by the authors. But the book would revolutionize your business thinking…�. Certainly, a good read.
A fantastic collection of classic writing on business strategy, which gave me lots to reflect on. Particular insights that resonated with me include:
-Operational effectiveness is not strategy. Strategy involves the 'creation of a unique and valuable position' requiring you to make trade offs - to choose what not to do. Strategy creates 'fit' among an organisation's many activities, ensuring they are integrated. It requires 'strong leaders willing to make choices'. (Michael Porter) -Successful organisations have a clear ideology, made up of 'core values' (a system of guiding principles and tenets) and 'core purpose' (the organisation's most fundamental reason for existence). Upon this, they build an effective vision - their environed future, their 'Big Hairy Audacious Goal'. (James Collins and Jerry Porras) -Transformative businesses are never just about discovery and commercialisation of great technology. Their success comes from 'enveloping new technology in an appropriate, powerful business model'. A great business model is built on a clear articulation of: a) a customer value proposition; b) a profit formula; and c) key resources and processes. (Mark Johnson, Clayton Christensen and Henning Kagermann) -Rather than thinking in terms beating the competition, it's better to do business where there is no competition. 'Make the competition irrelevant by creating a leap in value for both yourself and your customers'. Find a way of reducing your costs while offering your customers more value. (Cirque de Soleil did this by doing away with the costs of a traditional circus while offering customers a premium theatre-style experience) (W. Chan Kim and Renee Mauborgne). -Good strategy is only effective if it's implemented well. Most importantly, everyone needs to have a good idea of the 'decisions and actions for which he or she is responsible' (Gary Neilson, Karla Martin and Elizabeth Powers) -To implement strategy, it's important to focus on more than just short-term financial metrics. The 'balanced scorecard' suggests management should also focus on the customer experience, learning and growth and internal business processes. (Robert Kaplan and David Norton) -The anticipated benefits of strategy are not often fully realised. Top reasons for this are 'inadequate or unavailable resources' given to strategy implementation, poorly communicated strategy, and actions required to execute and not clearly defined. (Michael Mankins and Richard Steele)
A key 'meta' takeaway from the book for me is that good strategy is about clarity of thought. Organisations that do this well spend the time engaging in robust debate to get this right. Whether it's a values statement, a vision statement or a strategic principle, this clarity of thought is usually realised in very few words, with the idea's essence distilled to a pithy phrase ('low prices, every day' or 'democratise the automobile', for example). There is enormous power in this clarity, that can flow through an entire organisation.
I suspect I'll be drawing on this collection for some time to come.
W On Strategy dość mocno zderzyłem się z nową wiedzą, co mnie bardzo ucieszyło. Książka ma ciekawy format, jest to bowiem zbiór 10 artykułów opublikowanych wcześniej przez Harvard Business Review. Ten format sprawia, że dawka wiedzy, którą otrzymujemy jest wyczerpująca i na tyle skondensowana, że nie jesteśmy znużeni danym tematem. Poniżej kilka myśli z artykułów: 👉 Wiele firm myli tzw„Operational effectiveness� ze strategią. Bardzo łatwo sposoby pracy mogą zostać odtworzone przez konkurencje, przez co na danym rynku mamy dużo podobnych firm, które prowadza rywalizację tylko ceną. Strategią natomiast jest m.in. strategic positioning, który polega na robieniu innych rzeczy niż nasi rywale lub tych samych, ale w inny sposób. Z tym się wiąże robienie tzw trade offs, czyli świadome decydowanie czego nie robimy. Taki np Ryanair nie lata do Azji lub na duże główne lotniska, co pozwala ich zachować wyższą rentowność od konkurencji. 👉 Wyróżniamy 5 głównych sił, które mają znaczny wpływ na rentowność biznesu. Pozostając przy przykładzie Ryanair beda to: aktualna konkurencja (będzie pushowała ceny w dół), szukający oszczędności klienci (szukają najtańszej oferty na danej trasie), dostawcy (mamy tylko kilku głównych producentów samolotów pasażerskich, ich ceny nie beda niższe), nowi gracze (nowe firmy wchodzące na rynek), dostępne alternatywne sposoby zaspokojenia potrzeby klientów (zamiast samolotu możemy wybrać pociąg/samochód). 👉 Większość firm operuje w tzw „red ocean� - próbuje wyrwać co raz to większy kawałek tortu zapotrzebowania na dany produkt lub usługę. Im więcej jest konkurentów, tym ciężej jest o rozwój i wzrost zysków. Przeciwieństwem tego jest działanie w tzw „blue oceans�- wymyślasz nowe zapotrzebowanie, dostarczając klientom skok w wartości. Wcale to nie oznacza, że trzeba daleko odpłynąć od red ocean, wiele blue oceans pochodzi z branż będących red oceans. Takim dobrym przykładem może być Uber, który stworzył własny blue ocean, poprawiając trochę wartość jaką wcześniej oferowały użytkownikom bijące się o klientów korporacje taksówkarskie. 👉 Badacze zaobserwowali, że istnieje coś takiego jak Rule 80/100 (nie, nie pomyliłem zasady Pareto 80/20). Rule 80/100 mówi o tym, że lepiej mieć strategię w 80% dobrą i ją w całości wyegzekwować, niż mieć strategię 100% w punkt, ale położyć całkowicie egzekucję. Duża część książki dotyczy prawidłowej egzekucji. Można o tym bardzo dużo napisać, ale dwie sprawy są absolutnie kluczowe. Pierwsza to tzw decision rights - upewnienie się, że właściwi ludzi maja prawo do podjęcia decyzji w organizacji, najlepiej jak najbliżej wystąpienia danego problemu. Druga to information flow - praca nad tym, aby pomiędzy jednostkami lub częściami firmy informacje jak najlepiej przepływały.
Good book, but 2 out of 10 was read from other sources.
Table of Contents 1. What Is Strategy? Porter, Michael E. 2. The Five Competitive Forces That Shape Strategy Michael E. Porter 3. Building Your Company's Vision Collins, James C. and Porras, Jerry I. 4. Reinventing Your Business Model Mark W. Johnson, Clayton M. Christensen, and Henning Kagermann 5. Blue Ocean Strategy W. Chan Kim and Renée Mauborgne 6. The Secrets to Successful Strategy Execution Gary L. Neilson, Karla L. Martin, and Elizabeth Powers 7. Using the Balanced Scorecard as a Strategic Management System Robert S. Kaplan and David P. Norton 8. Transforming Corner-Office Strategy into Frontline Action Orit Gadiesh and James L. Gilbert 9. Turning Great Strategy into Great Performance Michael C. Mankins and Richard Steele 10. Who Has the D?: How Clear Decision Roles Enhance Organizational Performance Paul Rogers and Marcia Blenko
"Reinventing your business model" is also in "HBR's 10 Must Read on Business Model Innovation ". "Blue Ocean Strategy" is from book "Blue Ocean Strategy".
Strategy is making trde-offs in competing. Strategy is creating fitamong a company's activities.
A well-conceived vision consists of two major components: core idology & envisioned future.Purpose should last at least 100 years, it is like a guiding star on the horizon - forever pursued but never reached. For example: Disney's purpose is to make people happy, not to make cartoons. Vision requires 10 to 30 years of effort to complete. Our strategy and out mission may change, but our values never do.
Develop strategies to fulfill mission. A mission statement informs a company's culture. A strategy principle drives a company's strategy. A mission statement is aspirational: it gives people something to strive for. A strategic principle is action oriented: it enables people to do something now. A mission statement is meant to inspire frontline workers. A strategic principle enables them to act quickly by giving them explicit guidance to make strategically consistent choices. GE's mission statement: always with unyielding integrity, passionately focused on driving customer success, create an environment of stretch, excitement, informality and trust... The language is aspirational and emotional. GE's strategic principle: be #1 or #2 in every industry in which we compete or get out.
� Distinguish your company from rivals � Clarify what your company will and won't do � Craft a vision for an uncertain future � Create blue oceans of uncontested market space � Use the Balanced Scorecard to measure your strategy � Capture your strategy in a memorable phrase � Make priorities explicit � Allocate resources early � Clarify decision rights for faster decision making"
And this book is a collection of best-selling articles includes: featured article "What Is Strategy?" by Michael E. Porter, "The Five Competitive Forces That Shape Strategy," "Building Your Company's Vision," "Reinventing Your Business Model," "Blue Ocean Strategy," "The Secrets to Successful Strategy Execution," "Using the Balanced Scorecard as a Strategic Management System," "Transforming Corner-Office Strategy into Frontline Action," "Turning Great Strategy into Great Performance," and "Who Has the D? How Clear Decision Roles Enhance Organizational Performance.".
To many of author and perfective of this book to be feature and also to enrich our strategy perfective and side view of our strategy.
#bookstoread This week's pick is on #strategy. HBR's 10 Must Reads Series from Harvard Business Review provides a lot to reflect on. Here are my picks from the #book 1.Operational effectiveness is not a strategy. Strategy attempts to achieve sustainable competitive positioning. 2.Forces (customers, suppliers, competitors, entrants, offerings) shape your strategy. 3.Startegy should form long lasting company's vision. 4.Great business model is proposed by strategic positioning. 5.Follow blue ocean, don't enter red one. 6.Clarify decision rights and ensure info flows to support strategic efficiency. 7.Balanced score card is very supportive in strategic decision focus.
#Book HBR's 10 Must Reads Series on Strategy #thoughtleadership #strategy #business #leadership #strategicmindset
The year 2022, my reading goal was very clear to me, learning as much as possible about strategy. And strategy it has been.
On Strategy by Havard Business Review is the fifth book I am reading about strategy. This read was somewhat different because it contains short articles covering various aspects of strategy, with the first being the famously and widely read article by Michael Porter -What is strategy? It is like all the great brains in the subject of strategy have been assembled in one room.
By the end of the book, you should have a general outlook on how to:
1. Distinguish your company from Rivals 2. Clarify what your company will and won't do. 3. Craft a vision for an uncertain future 4. Create a blue ocean of uncontested market space 5. Use the balance scorecard to measure your strategy 6. Capture your strategy in a memorable phrase
And many more.
I would highly recommend this book to anyone who wants to explore the nuts and bolts of strategy.
A collection of essays on business strategy, ranging from the musings on the positioning and market competition to the overview of issues of internal communication in the top-down companies and identification of the final decisionmakers in a complex collaborations between multiple business units. Pretty good if you look past the huge amounts of corpspeak. The only issues I found with it were ocassional repetitions of facts and examples that are common for such compilations and that some parts of articles closer to the end sounded more as advertisement of new business methods for executives rather than educational materials.
Some articles definitely shine more than the others, so if you had time to read only 3, I'd suggest to read "What is strategy?", "Who has the D?" and "The five competitive forces that shape strategy".
This has proved an indispensable read. It starts with Michael E Porter’s seminal essay, ‘What is Strategy?�, defining strategy, and takes you all the way through to vision-setting, execution, successful implementation and decision-making. It allowed made me to pick the wheat from the chaff, providing the framework for distinguishing strategic positioning and core values, purpose and competencies. Even though the current edition is 10 years old and Porter’s original essay is 25 years old, rendering many of the case studies out of date, the thinking is so clear that it remains current and relatable. My copy is heavily underlined and bookmarked with post-its. A big thank you to the colleague who recommended it.
The book is an essential addition to any budding entrepreneur/ consultant. It manages to provide a base overview through some essential topics of consideration from strategy development to execution. If you've already explored strategy in the past, some of these reads will sound redundant, however, reading from HBR can give a new appreciation for the framework. Consider Porter's 5 Forces, for instance, a quintessential concept for most business students. While it's been mentioned to me for the past four years of my University career, I no doubt have a far deeper understanding of it because of the book.
While this book may not be for the most advanced business strategists, it's a great book for those looking to explore the landscape.
10 essays on strategy. Except probably only half of the essays were specifically about strategy formulation, the others were about operational effectiveness and/or execution.
I think about 3 of the essays were good and had an impact on my thinking when it came to strategy. I especially liked the first one. Thinking of businesses as collections of activities that have synergies, trade-offs and can be hard to imitate - that was a novel and useful idea to me.
It was interesting how the essays all use similar examples (e.g. Southwest airlines, Vanguard etc) and I suspect there are elements of survivorship bias in some of the anecdotes.
I would have rated this a lot higher if all 10 essays had been on strategy.
What Is Strategy by Michael Porter did not help me. I went back to the course material of Strategy I learned in GLOBIS MBA. The definition of "what is strategy" was concise and it helped me a lot.
The Five Competitive Forces.... by Michael Porter gave me an additional understanding that a company is actually competing with its suppliers and customers.
The most useful for me in my startup phase of my company is Building Your Company's Vision by Jim Collins and Jerry Porras. I realized that we have room to sharpen and redefine Mission, Vision and Values, which I believe will help crystalize what we do to absolute essence.
The rest, I will come back later when I will need them. Not now.
This book is indeed what it says to be, a collection of the top 10 articles on strategy. These articles seem to be based on the authors books, and their key principles. Even thought this book offers great strategic insights, I found the chapters be too narrow on the actual concepts that they represent. Therefore this book is more for getting your feet wet on these concepts of strategy, deeper study is required to fully understand all the ins and outs of these concepts. Looking forward to reading the other HBR's 10 must reads - maybe strategy is not the best subject to be so narrowly packed, it indeed is a complicated manner.
Decent book outlining how to do strategy within a corporation. I’m not business magnate, though the lessons were still instructive. The case studies are from the late 90s and early 2000s, so it is interesting to see what was important to companies at that time. Some of the companies that were praised are now defunct or not near what they were (AOL, Philip Morris, Nano). It was nice not to have the typical businesses you here about today as they just weren’t really around yet.
All in all, decent advice and we’ll illustrated with call outs and stories. Useful as a volume to look over from time to time as situations arise that need some additional light.
The book's cover title says it all - "If you've read nothing else on strategy, read these definitive articles from HBR". I found almost all the articles presented in this book very enlightening and filled with a lot of "aha" moments. Especially the first 2 articles by Michael Porter are just gold. The book is written in Harvard's traditional case study method and may be a bit jargon heavy specifically for users who come from a non-management background/expertise but is a very fulfilling read for any professional who wants to expand his knowledge regarding strategising.
Not so much a book per se than a collection of articles from a pretty solid cast of contributors. For those interested in this type of thing, some strong pieces on business strategy/ strategic management with good linss to real world examples. (Some a bit dated... soubt the AOL-Time Warner merger is anything to celebrate in hindsight) Also, a few parts a little 'hot air'-y and potentially worth a skip. Overall, a few frameworks and angles of thinking that I can apply to my daily work in srategy. Good read.
I used this book for my Strategy class in Oxford. Strategy could be quite boring and daunting topic to study for a finance student. However this book will make you love strategy with its engaging and exciting literature. Short but robust articles supported with real case scenarios. This book will ensure you understand why strategy is the most important thing in an organisation whatever you are doing
Pohledy na strategii od high-level Porterovy klasiky What is strategy přes formulování vize až k přenosu dílčích rozhodnutí na nižší úrovně a přenos strategie do běžného fungování firmy. Pozdější kusy mi přišly už trochu roztahané.
Minimálně jako námět k přemýšlení určitě hodnotné a některé věci mi přijdou relativně rychle implementovatelné v menší firmě. Do půl roku bych chtěl aspoň něco z toho u nás zavést.
There are insightful articles on strategy covering many examples. This is a good start to understand strategic viewpoints with practical takeaways. There are some overlaps in articles, which make it repetitive and somewhat lengthy. Overall, a useful collection, handpicked after careful consideration from HBR. Worth a read!
Reading HRB articles is a basis of understanding business. HBR has to control the translation of their editions and never leave them to independent institutions without reviewing. Some of the articles contain very old ideas and many revisions came after it, I wish that revisions were mentioned at the margins, at least.