Sufism: An Introduction to the Mystical Tradition of IslamMay 10 2011by Carl W. Ernst Ph.D.
Sufism and Taoism: A Comparative Study of Key Philosophical ConceptsAug 6 1984by Toshihiko Izutsu
Sufism for Non-Sufis?: Ibn 'Ata' Allah al-Sakandari's Taj al-'ArusJun 25 2012by Sherman A. Jackson
Sufism: Veil and Quintessence A New Translation with Selected LettersDec 11 2006by Frithjof Schuon and James Cutsinger