Imaginary Muslims

Readers of Corbin's Creative Imagination will know of his fondness for the Uwaysi Sufis. This book is as far as I know the only one in English that discusses these people:

Baldick, Julian. Imaginary Muslims: The Uwaysi Sufis of Central Asia. Washington Square, New York: New York University Press, 1993.

Reviews of the books can be found here:

Review by Robert Irwin, Bulletin of the School of Oriental and African Studies, University of London, Vol. 58, No. 1 (1995), pp. 139-140.

Review by Alexander Knysh, Journal of the Royal Asiatic Society, Third Series, Vol. 5, No. 1 (Apr., 1995), pp. 103-106.

See also Baldick's later work:

Baldick, Julian. Animal and Shaman: Ancient Religions of Central Asia. New York: New York University Press, 2000