Akahira, Y. and Beig, D. 1967. Comparative study of Corpora alata in brazilian stingless bees. Papéis Avulsos de Zoologia. 20, 1-21 (1967) (Jul. 1967), 165–190. DOI:https://doi.org/10.11606/0031-1049.1967.20p165-190.