When I was working for my dad in the music store, I noticed that there wasn't too much material in those days for drums. It was always, here's how you hold the left hand, the right hand. They didn't even talk about matched grip then. It was all conventional grip. So I decided to write some exercises that would help drummers - not only drummers, but brass instrument players and reed players, because rhythm is part of their lives too. So I wrote 400 pages on 4/4 only, 400 pages on 3/4 only, 400 pages on 4. Then I got into complex odd times. The reason Gil Breines name is on there is he  condensed those down to maybe a hundred pages each book, or less than that? I don't know how many pages are in the book.