Louis Dupree, Afghanistan. 1st Edition: 1973; Ludwig W. Adamec, Historical Dictionary of Afghanistan, 3rd ed., 2003.
S. I. Bruk, Narody Peredney Azii (1960); S.I. Bruk, and V. S. Apenchenko, Atlas Narodov Mira (Moscow: Academy of Science, 1964) A. Gabriel, Religionsgeographie von Persien (Vienna, 1971).
