Reference

S. G. Bogoyavlenskiy (1972): From nectar to yield; [Ru; 4 tabs. 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) – : 71 - 77.