this book, "Theory of Viscoelasticity" by R. M. Christensen, is a valuable resource for engineers and researchers interested in viscoelastic materials. written by an active contributor to the field, the book provides a thorough development of the phenomenological theory of viscoelastic materials. while the physical processes underlying the time-dependent behavior are only briefly mentioned, the mathematical aspects of the theory are emphasized, with a focus on their relevance to practical applications. the book includes a discussion of experimental results and covers seven chapters on topics such as viscoelastic stress-strain constitutive relations, isothermal boundary-value problems, thermoviscoelasticity, wave propagation, general theorems and formulations, nonlinear viscoelasticity, and determination of mechanical properties. an appendix on generalized functions, laplace transforms, and approximate inversion of laplace transforms is also included. each chapter is followed by an extensive list of references, helping to develop a historical perspective, and the first five chapters contain several exercises. aside from being a good reference source, the book could serve as a text for a graduate course in viscoelasticity. however, it would be essential that such a course be preceded by a course in linear elasticity, and preferably by a course in general continuum mechanics.this book, "Theory of Viscoelasticity" by R. M. Christensen, is a valuable resource for engineers and researchers interested in viscoelastic materials. written by an active contributor to the field, the book provides a thorough development of the phenomenological theory of viscoelastic materials. while the physical processes underlying the time-dependent behavior are only briefly mentioned, the mathematical aspects of the theory are emphasized, with a focus on their relevance to practical applications. the book includes a discussion of experimental results and covers seven chapters on topics such as viscoelastic stress-strain constitutive relations, isothermal boundary-value problems, thermoviscoelasticity, wave propagation, general theorems and formulations, nonlinear viscoelasticity, and determination of mechanical properties. an appendix on generalized functions, laplace transforms, and approximate inversion of laplace transforms is also included. each chapter is followed by an extensive list of references, helping to develop a historical perspective, and the first five chapters contain several exercises. aside from being a good reference source, the book could serve as a text for a graduate course in viscoelasticity. however, it would be essential that such a course be preceded by a course in linear elasticity, and preferably by a course in general continuum mechanics.