Calonje, M., G. Morales, C. López-Gallego, and F. J. Roldán. “A Taxonomic Revision of Zamia montana and Zamia oligodonta, With Notes on Their Conservation Status”. Phytotaxa, vol. 192, no. 4, Jan. 2015, pp. 279–289, doi:10.11646/phytotaxa.192.4.5.