Vivallo, F. and Zanella, F.C.V. 2021. Relicthemisia, a new subgenus of the oil-collecting bee genus Centris Fabricius, 1804 with notes on distribution and host plants of C. xanthomelaena Moure & Castro, 2001 (Hymenoptera: Apidae). European Journal of Taxonomy. 760, 1 (Jul. 2021), 1-15. DOI:https://doi.org/10.5852/ejt.2021.760.1435.