C. da . Cruz-Landim, R. D. . Reginato, and V. L. . Imperatriz-Fonseca, “Variation on ovariole number in meliponinae (Hymenoptera, Apidae) queen’s ovaries, with comments on ovary development and caste differentiation”, Pap. Avulsos Zool., vol. 40, pp. 289–296, Feb. 1997, doi: 10.11606/0031-1049.1997.40.p289-296.