Population of Yakutia on the eve of the Great Patriotic War: new research approaches

Basing upon the archival data of 1938-1941, introduced for scientific use for the first time, the article considers aspects of All-Union census in the Yakut ASSR on the eve of the Great Patriotic War in 1939 (official census date is 17.01.1939). The author compares demographic data determining the population size. It is concluded, that the census data of 1939 show demographic situation in the Republic as of late 1939 - early 1940, rather than January, 1939.