J. Alcocer, A. Lugo, M. del R. Sánchez, E. Escobar, and M. Sánchez, “Bacterioplankton from cenotes and anchialine caves of Quintana Roo, Yucatan Peninsula, Mexico”, Rev. Biol. Trop., vol. 47, no. S1, pp. 19–25, Mar. 1999.