Start with high-confidence yoga books, then narrow by subgenre or adjacent topics.
The Stories Behind the Poses
Dr. Raj Balkaran, Raj Balkaran
The Heart of Yoga
T. K. V. Desikachar
The Yamas & Niyamas
Deborah Adele
The Amazing Secrets of the Yogi
Charles F. Haanel
Restoring Prana
Robin L. Rothenberg, Kirsteen Wright
Charles F. Haanel, Unknown Author