^Elior, Rachel, Jewish Mysticism: The Infinite Expression of Freedom, Oxford. Portland, Oregon: The Littman Library of Jewish Civilization, 2007.
^A.E. Waite. Rosicrucian Rites and Ceremonies of the Fellowship of the Rosy Cross by Founder of the Holy Order of the Golden Dawn. Ishtar, 2008. ISBN 978-0-9783883-4-8
^Krishna Chattopadhyay. The world of mystics: A comparative study of Baul, Sufi and Sikh mysticism. R.K. Prakashan, 1993.
^Harold D Roth. Original Tao: Inward Training (Nei-yeh) and the Foundations of Taoist Mysticism. Columbia University Press. New Edition, 2004. ISBN 978-0-231-11565-0