Ken Cohen's stuff is really good. I read that book specifically years ago but I don't remember the details. What I do remember is that Ken's material is effective and slightly less risky than some other qigong teachers. If you get his 100 day qigong course, you get most everything that he has to teach all in one package, which is good because he has a way of teaching that blends the material together very well. I say that because people tend to take a pice of one system here and one piece from there and then try to make it all work when most of the time what they're doing is contradictory. Ken combines his systems in ways that don't conflict, allowing you get get many benefits without the potential problems.
