1. The structure and development of the external genitalia of Thysanura and Hymenoptera;Bekker;Trud. nauchno-issledovab. Inst. Zool. Moscow,1925
2. Zur Frage von der Homologie des männliehen und weiblichen äusseren Genitalapparates der Hymenopteren. [In Eussian with German summary.];Bekker;Rev. zool. russe,1930
3. Fertilization in the honey bee. I. The male sexual- organs: their histological structure and physiological functioning;Bishop;J. exp. Zool.,1920
4. Fertilization in the honey-bee. II. Disposal of the sexual fluids in the organs of the female;Bishop;J. exp. Zool.,1920