Hofmann, Murad Wilfried. “Richard Gramlich. Der Eine Gott — Grundzüge Der Mystik Des Islamischen Monotheismus [The One God — Principal Features of the Mysticism of Islamic Monotheism]”. Islamic Studies 46, no. 1 (March 31, 2007): 124-131. Accessed January 15, 2025. http://irigs.iiu.edu.pk:64447/ojs/index.php/islamicstudies/article/view/4296.