1. Beig D., 1972.—The production of males in queenright colonies ofTrigona (Scaptotrigona) postica.J. Apic. Res., 11, 33–39.
2. Defrisse-Gussenhoven E., 1955.—Ellipses équiprobables et taux d'éloignement en biométrie.Bull. Inst. Royal Sci. Nat. Belgique, 26, 1–30.
3. Dzierzon J., 1845.—Eichstädter Bienenzeitung, 11, 109–113;12, 119–121.
4. Kerr W.E., Krause W., 1950.—Contribuição para o conhecimento da bionomia dos Meliponini. Fecundação da rainha emMelipona quadrifasciata Lep. (Hym., Apidæ).Dusenia, 1, 275–282.
5. Kramer C.Y., 1972.—A first course in methods of multivariate analysis. Virginia Polytechnic Institute and State University Polytechnic Institute, Virginia, 351 p.