Baker, D. B. (2002) „On Palaearctic and Oriental species of the genera Pseudapis W.F. Kirby, 1900, and Nomiapis Cockerell, 1919 (Hymenoptera, Halictidae, Nomiinae)“., Beiträge zur Entomologie = Contributions to Entomology, 52(1), S. 1–83. doi: 10.21248/contrib.entomol.52.1.1-83.