Romo-Campos, L., J. L. Flores-Flores, J. Flores, and G. Álvarez-Fuentes. “Seed Germination of Opuntia Species from an Aridity Gradient in Central Mexico”. Journal of the Professional Association for Cactus Development, vol. 12, Nov. 2010, pp. 181-98, doi:10.56890/jpacd.v12i.107.