Limits of threcycle speech in 1773 according to official data

Petrov, Alexey Leonidovich (1899-1932).The limits of the threarent speech in 1773 on official data: research and cards / A. Petrov.- St. Petersburg: Type.M-Wa Put.Post., 1911. - [4], x, 337 p., 7 liters.kart.;23. - (Notes of the Historical and Philology Faculty of Imperial Saint-Petersburg University; Ch. 105).Electronic Source: PB