This book is an intriguing look at Qigong, martial arts and the way of the Ninja. If nothing else the reference listing in the book is worth reviewing.

 

Yoga Psychology
Title: Yoga & Psychotherapy
Author: Swami Rama, Rudolph Ballentine, MD, Swami Ajaya, PHD
Publisher: Himalayan Institute Press
ISBN-13: 978-0-89389-036-0
ISBN-10: 0-89389-036-7
Comments:
While this is a rather dry book, it does try to explain states of mind within meditative states and the connection between brain wave states and meditation.
The book also demonstrates the commonality of breathwork and energy across cultures.

 

Title: Yoga Sutras of Patanjali as interpreted by Mukunda Stiles
Author: Mukunda Stiles, 2002
Publisher: Red Wheel/Wenser, LLC
ISBN: 1-57863-201-3

Comments:
A good translation of the Yoga sutures and the levels of consciousness that one ascends on through yoga and the multi-fold path.