This book is in two Parts, viz. Cryogenic Engineering: Software solutions – Part-III-A and Part-III B. and deals with the topic: Cryogenic refrigeration systems.Part-III-A contains a brief summary of background theory, formulas and the problems solved with Mathcad. Part-III B contains problems solved with Engineering Equation Solver (EES).In Part-III-B, many Functions and Procedures are written using Engineering Equation Solver (EES) and problems are solved to illustrate the use of these Functions/ Procedures.EES has a great advantage that it has built-in Functions for properties of most of the cryogenic fluids and materials.Along with this free ebook, two ZIP files are available for free: ‘Cryogenic liquefn. systems – distributables’ and ‘Cryogenic refrign. systems – distributables’. They contain, totally 28 ‘stand- alone’ programs, originally written in EES.Students, teachers, researchers and professionals may find them very useful.