Reference

Eduard Friedrich von Eversmann (1846): Die Brutstellen des Hylaeus quadricinctus FABR. [De; 4 col. figs. on Pl. III. Date: 29.X.1845, 1846]. – Bull. Imp. Soc. Nat. Moscou (Moscow) – 19 (pt 1, no. 1): 188 - 193.