Reference

V. S. Grebennikov (1972): On problems of the conservation of bumble bees as important pollinators; [Ru; 1 fig., 9 refs. Date: 12.V.1972]. – In: SKUFIN, K. V. (ed.). Nature Conservation and Rational Utilisation of Nature Resources in the Central Chernozem Zone. [A Col-lection of Papers]. Voronezh (Voronezh State University) – : 78 - 82.