I'm glad you liked the book. I know Mr. Christensen and Wim Demeere pretty well. In fact I'll be seeing Mr. Demeere in July (he's from Belgium).
I believe I (Frank Garza) am mentioned in that book.
If you get a chance, read Loren Christensen's Way Alone book. I read the first version of it many years ago and it inspired me to train harder.
Mr. Christensen is a retired Portland (Oregon) police officer and martial artist, and he has a lot of great knowledge.