Lisa, what kind of yoga book are you looking for? Something pretty with pictures of poses, something with really good descriptions, something with Sanskrit, a certain style of yoga?
I literally have over an 100 yoga books. I was a teacher for many years. The yoga "Bible" is B.K.S. Iyengar's "Light on Yoga". It is not fancy, the pictures are black and white but it has exact instructions of almost every pose you could ever think of. Of course he teaches Iyengar style yoga. It has practice programs and also a lot of instructions for pranayama. It's the classic.
PS- I've never heard of the authors you mentioned.