Reference

N. N. Blagoveshchenskaya (1988): Nest aggregations of wild bees and prospectives of their reservation in the Middle Volga basin; [Ru; 2 refs. Date: 17.VI.1988]. – In: GORELOV, M. S. (ed.). Reservation of Animals in the Middle Volga Basin. An Inter-College Collection of Scientific Papers. Kuybyshev (Kuybyshev State Pedagogical Institute) – : 34 - 37.