Principles of Economics. Illustrated

Principles of Economics is  magnum opus of Alfred Marshall. It was the standard text for generations of economics students.
Marshal's  plan for the work gradually extended to a two-volume compilation on the whole of economic thought.
Marshall's influence on modifying economic thought is difficult to deny. He popularized the use of supply and demand functions as tools of price determination; modern economists owe the linkage between price shifts and curve shifts to Marshall.