Reference

V. I. Blinnikov, V. P. Naumkin, N. I. Kulikov (2000): Bumble bees of the Orel province; [Ru; 1 fig., 3 tabs. Date: [31.XII].2000]. – In: NAUMKIN, V. P. (ed.). A Collection of Scientific Papers on Apiculture. No. 4. Orel (Orel State Agricultural University) – : 101 - 115.