- ↑ (2008) , manuscript, World Bee Checklist Project - update 2008-09
- ↑ Williams, P. H. (1998) An annotated checklist of bumble bees with an analysis of patterns of description (Hymenoptera: Apidae, Bombini), Bulletin of the Natural History Museum (Entomology), vol. 67, no. 1
- ↑ (2006) , Manuscript, Checklist of Apoidea of North America... - 12 Oktubre 2006
- ↑ (2006) , website, Bombus - bumblebees of the world
- ↑ Hines, Heather M., Sydney A. Cameron, and Paul H. Williams (2006) Molecular phylogeny of the bumble bee subgenus Pyrobombus (Hymenoptera: Apidae: Bombus) with insights into gene utility for lower-level analysis, Invertebrate Systematics, vol. 20, no. 3
- ↑ 6.0 6.1 Bisby F.A., Roskov Y.R., Orrell T.M., Nicolson D., Paglinawan L.E., Bailly N., Kirk P.M., Bourgoin T., Baillargeon G., Ouvrard D. (ed.) (2011). "Species 2000 & ITIS Catalogue of Life: 2011 Annual Checklist". Species 2000: Reading, UK. Ginkuhà 24 Septyembre 2012.CS1 maint: multiple names: authors list (link) CS1 maint: extra text: authors list (link)
- ↑ ITIS Bees: World Bee Checklist. Ruggiero M. (project leader), Ascher J. et al., 28 Septyembre 2009
