The textbook introduces the largest documentary complexes of Russian and foreign archives, manuscript departments of museums and libraries, as well as the history and modern organization of their scientific reference apparatus. Researchers gain guidance and insight into information retrieval tools at the level of archives, foundations, archival files, and documents. For students, graduate students, teachers and everyone interested in Russian history, as well as the problems of preserving and using retrospective documentary information as an integral part of national and world information resources.