BioStor
 | Classification and phylogenetic relationships of the panurgine bees: the Calliopsini and allies (Hymenoptera: Andrenidae) (1991) University of Kansas Science Bulletin 54: 209-256 |
 | A Survey of the Bees of the Black Rock Forest Preserve, New York (Hymenoptera: Apoidea) Valerie Giles and John S Ascher (2006) Journal of Hymenoptera Research 15: 208-231 |