Tovar-Puente, A. ., Pando-Moreno, M. ., González-Rodríguez, H. G.-R., Scott-Morales, L. . and Méndez-Gallegos, S. de J. . (2007) “Density of Calcium Oxalate Crystals in 15 Prickly Pear Cultivated Species”, Journal of the Professional Association for Cactus Development, 9, pp. 91–98. doi: 10.56890/jpacd.v9i.267.