The collection includes documents of the 19th - early 20th centuries stored in the Central State Archives of the Republic of Kazakhstan (TsGA RK), state archives of Uzbekistan (TsGA RU) and Russia (RGIA), as well as materials from rare funds of scientific libraries of the post-Soviet republics. Most of these sources are published for the first time. The collected materials can be used by source scientists, religious scholars, cultural scientists, political scientists, scientists of other specialties.