Paramhamsa Yogananda

Thirumoolar 

* Online version with English translation freely available at Himalayan Academy Website

Earlyne Chaney

* Totally eight degrees (eight volumes) listed in Amazon. You can check them all.

Rajarsi Nandy

Venkatesh

* Available on Amazon, Noolulagam or Marina websites. Same author also published Yoga Vedham (Kiriya Yogam unakul).

Yogani

Ennio Nimis

Sri Sakthi Sumanan

Sathguru Sivaya Subramaniya Swami

Aidan Wachter

Ben Woodcroft

Swami Satyananda Saraswati

Zanna Blaise

Jiddu Krishnamurti

Jurgen Ziewe