Machado, T. M., M. O. D. Pivari, and L. M. Versieux. “Expanding Waltillia: An Addition to a Previously Monotypic Genus of Bromeliaceae from the Espinhaço Range, Brazil”. Phytotaxa, vol. 491, no. 1, Mar. 2021, pp. 1–11, doi:10.11646/phytotaxa.491.1.1.