Hatha Yoga Pradipika. Introduced in english by Yogi Shreyananda Natha!
Is the No.1 most read book about yoga besides Patanjalis Yogasutras. The Hatha Yoga Pradipika, along with the Gheranda-Samhita (1650), is one of the most detailed manuals describing the techniques of Hatha Yoga. The book is the hatha yoga text that has historically been studied within yoga teacher training programmes, alongside texts on classical yoga such as Patanjali''s Yoga Sutras.