Khan, Hazrat Inayat
The Sufi International Headquarter's, 1956
Buku Teks
Muhammad Luthfi Ubaidillah
Program Pascasarjana Universitas Indonesia, 2004
UI - Tesis (Membership)
Naupal
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2015
UI - Publikasi
Hall, Harrison
Wadsworth, 1986
Buku Teks
Landau, Rom, 1899-
George Allen and Unwin, 1959
Buku Teks