Phylogenetic analysis of the corbiculate bee tribes based on 12 nuclear protein-coding genes (Hymenoptera: Apoidea: Apidae) Atsushi Kawakita, John S. Ascher, Teiji Sota, Makoto Kato and David W. RoubikApidologie, 39 1 (2008) 163-175DOI: https://doi.org/10.1051/apido:2007046