Bearman, P., Th. Bianquis, C.E. Bosworth, E. van Donzel, and W.P. Heinrichs, eds. Encyclopaedia of Islam, Second Edition. Brill Online, 2010.

The Encyclopaedia of Islam is an excellent source of information on Islamic regions in general, especially if you have online access.  As for Central Asia, it includes entries for its countries, cities, people, historical figures, literary works, movements, and even kumis (fermented mares milk).  From these entries, and others, basic information about the history, repression, and pracitce of Islam in historical and present day Central Asia can be found.  Descriptors: 2010s, B, bibliographic, D, encyclopedia, H, post-Soviet, pre-Tsarist, Soviet, Tsarist.