In this third edition the book has been expanded in three directions: 1. Problems have been added at the end of each chapter (40% of which are solved in the last section of the book) together with suggestions for further reading. Furthermore, the number of appendices (marked with a grey stripe) has been substantially enlarged in order to make the book more self-su?cient. These additions, together with many clari?cations in the text, render the book more suitable as a companion in a course on Green s functions and their applications. 2....