From the book reviews: "This book is the second edition of the classic 1990 text ... and inherits much of the structure and all of the virtues of the original. ... this is a deep and important book, which would reward further study as the focus of a reading group or graduate course, and comes enthusiastically recommended." (Oliver Johnson, Mathematical Reviews, October, 2014) "In Entropy and Information Theory Robert Gray offers an excellent text to stimulate research in this field. ... Entropy and Information Theory is highly recommended as essential reading to academics and researchers in the field, especially to engineers interested in the mathematical aspects and mathematicians interested in the engineering applications. ... it will contribute to further synergy between the two fields and the deepening of research efforts." (Ina Fourie, Online Information Review, Vol. 36 (3), 2012) "The book offers interesting and very important information about the theory of probabilistic information measures and their application to coding theorems for information sources and noisy channels. The main goal is a general development of Shannon's mathematical theory of communication for single-user systems. ... The author manages to balance the practice with the theory, every chapter is very well structured and has high-value content." (Nicolae Constantinescu, Zentralblatt MATH, Vol. 1216, 2011)