TIZNADO-HERNÁNDEZ, M. E.; FORTIZ-HERNÁNDEZ, J.; OJEDA-CONTRERAS, Ángel J.; RODRÍGUEZ-FÉLIX, A. Use of the elliptical mathematical formula to estimate the surface area of cladodes in four varieties of Opuntia ficus-indica. Journal of the Professional Association for Cactus Development, [S. l.], v. 12, p. 98–109, 2010. DOI: 10.56890/jpacd.v12i.101. Disponível em: https://www.jpacd.org/jpacd/article/view/101. Acesso em: 16 oct. 2025.