Silveira, F. A. “A Synopsis of Actenosigynes Moure, Graf &Amp; Urban, 1999 (Hymenoptera: Colletidae)—new Species, Possible Oligolecty and Biogeographic Comments”. Zootaxa, vol. 2292, no. 1, Nov. 2009, pp. 15–24, doi:10.11646/zootaxa.2292.1.2.