'The book commands an impressive bibliography of 396 references, making it an invaluable reference for any researcher who wishes to get into this area of research. The authors have done the best job possible to present this work as carefully and clearly as possible. I strongly recommend the book to everyone who wishes to master this research area, as well as everyone who wants to learn more about the proper orthogonal decomposition method. The research program detailed by the authors is a very promising approach to the problem of the coherent structures of turbulence. Active turbulence researchers, especially researchers who are mainly focused in the engineering applications of turbulence, will find this book a welcome addition to their library.' Eleftherios Gkioulekas, SIAM News