If you have read any book that tells you how to make a Bock Style I can almost guarantee you that they are actually quoting this book. Darryl Richman is a beautiful and clear writer who explains the triple decoction method better than just about any other writer, or they are drawing from this book. This is a classic.
This book is fairly advanced and I would not recommend this series for the beginner or low experience brewer as Richman does give some very technical descriptions about mash chemistry which are important to understand for this style but would be very overwhelming if you are starting out. If you are an advanced brewer, this is a beautiful series and should be read by everyone as this series shows up in the reference section of almost all of the books I have read.