The Dervishes or Oriental Spiritualism by Johan P Brown

Dervishes in an invaluable contribution to the study of the Belief and spiritual principles of the Darvish Orders and is perhaps one of the rare (if not the only) and most accurate work on the subject. Drawn exclusively from the original Oriental works and from Turkish, Arabic and Persian MSS, the originality and authenticity of the work is beyond doubt. 

Publisher - Gulshan Books