A great expert in the use of computers, Prager published Introduction to basic FORTRAN programming and numerical methods in 1965.
Hamming describes the work as follows:- The basic aspects of FORTRAN are very well described, and many useful remarks are given to aid the student and point out common pitfalls of the beginner.
The outbreak of war in 1939 was distressing to Prager and the German advances by 1940 made him decide that he would be best placed if he could emigrate to the United States.
Then in 1929, when he was only 26 years old, Prager was appointed to act as Director of the Institute of Applied Mathematics at Göttingen.
In 1932 Prager was appointed as Professor of Technical Mechanics at Karlsruhe.
Prager further developed the material given in these lectures and presented it in an English version in An introduction to plasticity published in 1959.
A review of this book, this time by J Heyman, again gives Prager high praise:- There are no spare lines and there is no padding; the author has considered every word, and thought deeply on every aspect of plastic theory. the author is completely master of this, his main field of study, and he communicates this sense of mastery to the reader.
The Lectures were published as The extremum principles of the mathematical theory of elasticity and their use in stress analysis in 1950.
An important monograph, which Prager wrote jointly with P G Hodge, was Theory of perfectly plastic solids (1951).The numerical methods aspect also shows the hand of a master and covers all the material that is usually given in a one term course, including ordinary differential equations, in a reasonably rigorous and at the same time practical manner. All in all it is a remarkable book and one wonders how the author managed to cover so much, so smoothly and unhurriedly as he has.Prager retired from Brown University in 1973 and moved to Savignon, Switzerland, where he continued to undertake research, write books, give lecture tours, and edit journals.These were published in the following year as Probleme der Plastizitätstheorie The book constitutes a clear and penetrating exposition of the concepts and applications of the theory of plasticity.The author is one of the principal contributors in the field and his book provides the reader with indications of the impending developments of the theory.while the English one is Introduction to mechanics of continua.