Feuillet, C., L. E. Skog, and D. Barabé. “Paradrymonia Badia (Gesneriaceae), a New Species from the Guiana Shield”. Journal of the Botanical Research Institute of Texas, Vol. 12, no. 2, Nov. 2018, pp. 549-54, https://journals.brit.org/jbrit/article/view/959.