E. J. Rincón Barón, B. E. Guerra Sierra, A. X. Sandoval, and S. Espinosa, “Ontogeny of sporangia and sporogenesis of the fern Phymatosorus scolopendria (Polypodiaceae)”, Rev. Biol. Trop., vol. 68, no. 2, pp. 655–668, Jun. 2020.