The History of Tatar ASSR, at last published in 1955, took a position close to the 1946 conference, although it did not claim the Russians influence on the Tatar ethnogenesis (while stressing close contacts between the Russians and the Bulghars-Tatars), as outright Russo-centricism faded away after Stalins death in 1953. The books authors wrote that the process of creating a unified Bulghar people had been stopped by the Mongol invasion, which, however, had not greatly changed the ethnic composition of the region. According to them, the process of formation of the Kazan Tatars was finished in the Kazan khanate mainly on the basis of the Bulghars and, partly, the Kipchaks and other Turkic tribes. Deviating from the multidisciplinary tradition of Soviet ethno-genetics, this book attached extraordinary importance to language, and claimed that the Bulghar language and the modern Kazan Tatar language were one and the same.