From the reviews:
The present volume contains thirty selected articles of D. Mumford on topics in algebraic geometry ... . must be seen as a highly valuable and welcome collection for every researcher in the field. ... Further generations of researchers in this field, graduate students, mathematical physicists, and mathematical historians will profit a great deal from this collection of selected papers ... . this is why this volume is at least a must for any relevant library. (Werner Kleinert, Zentralblatt MATH, Vol. 1051)
Selected Papers Volume II collects twenty-nine articles by Mumford, along with four previously unpublished pieces and dozens of letters between Mumford and Grothendieck. ... this book the same way I felt about the first volume: this is a book that most algebraic geometers - and all libraries - will not want to do without. (Darren Glass, The Mathematical Association of America, October, 2010)
The present second volume of David Mumford's papers on algebraic geometry, including his correspondence with Alexandre Grothendieck over a period of twenty-five years, must be seen as another hoard of Jewels from his treasury of mathematical writings. ... this book contains a wealth of new information for the reader, and it is an utmost useful reference book moreover. ... this book decidedly ought to be added to the private library of any algebraic geometer. (Werner Kleinert, Zentralblatt MATH, Vol. 1211, 2011)