From the reviews of the third edition:
"The main purpose of this book is to provide graduate students, and also experienced researchers, with a clear and quite detailed survey of the applications of Green’s functions in different modern fields of quantum physics. ... In summary, this book is a good manual for people who want to understand the physics and the various applications of Green’s functions in modern fields of physics. It can also be used as a starting point for studying numerical analysis in condensed matter theory." (Jean-Yves-Fortin, Mathematical Reviews, Issue, 2007 i)