M. F. M. Mendes, T. M. Francoy, P. Nunes-Silva, C. Menezes, and V. L. Imperatriz-Fonseca, “Intra-populational variability of Nannotrigona testaceicornis Lepeletier 1836 (Hymenoptera, Meliponini) using relative warps analysis”, Biosci. J., vol. 23, Dec. 2007.