Swami Vivekananda 
Raja Yoga [EPUB ebook] 

* This is the extended edition including an extensive preface by Swami Vivekananda, the chief disciple of the 19th century mystic Ramakrishna Paramahansa and the founder of the Ramakrishna Math and the Ramakrishna Mission. He gives us deep insights about Yoga and the Ultimate Goal of Life.
Yoga is a subject which has enthralled the attention of the world from time out of mind. No one has really done justice to such a grand system, though there have been, now and then, innumerable attempts.
Contents:
Preface
Introductory
The First Steps
Prana
The Psychic Prana
The Control Of The Psychic Prana
Pratyahara And Dharana
Dhyana And Samadhi
Raja-Yoga In Brief
Patanjali’s Yoga Aphorisms
Introduction
Concentration: Its Spiritual Uses
Concentration: Its Practice
Powers
Independence