M. Díaz-Betancourt, L. Ghennandi, A. Ladio, I. R. López-Moreno, E. Raffaele, and E. H. Rapoport, “Weeds as a source for human consumption. A comparison between tropical and temperate Latin America”, Rev. Biol. Trop., vol. 47, no. 3, pp. 329–338, Sep. 1999.