a community of practitioners
I don't really think there are other books about Chi Nei tsang that I'm aware of. But I took a class at Mueller that used the Mantak Chia book really enjoyed it. I found that Chi Nei Tsang was very useful in treating a client with MS was able to get it to go away. Not sure why it did I just used the theory that it had to be caused by weak organs and Chi Nei Tsang strengthend them.