Reference

N. N. Blagoveshchenskaya (1971): On the utilisation of bees (Hymenoptera, Apoidea), forming nest aggregations, in agriculture. [Ru; 6 refs. Date: 16.II.1971]. – Uchen. Zapiski Ulyanovsk. Ped. Inst., Biol. (Ulyanovsk), – 21 (6): 91 - 97.