C. R. Martínez-González, J. D. J. Morales-Sandoval, C. A. González-Martínez, J. Jiménez-Ramírez, and C. Gallegos-Vázquez, “Opuntia tehuacana and O. olmeca (Cactaceae, Opuntioideae) are to be considered as ascribed to a single species: morphological and molecular evidences”, Phytotaxa, vol. 479, no. 2, pp. 160–172, Jan. 2021.