J. C. Biesmeijer, E. J. Slaa, M. S. de Castro, B. F. Viana, A. de M. P. Kleinert, and V. L. Imperatriz-Fonseca, “Connectance of Brazilian social bee: food plant networks is influenced by habitat, but not by latitude, altitude or network size”, Biota Neotrop., vol. 5, no. 1, Jan. 2005.