Müller, A. 2017.

Palaearctic Protosmia bees of the subgenus Chelostomopsis (Megachilidae, Osmiini): biology, taxonomy and key to species

. Zootaxa. 4227, 2 (Feb. 2017), 287–294. DOI:https://doi.org/10.11646/zootaxa.4227.2.9.