De Block, Petra. “Monograph of the Western Indian Ocean Genus Paracephaelis (Rubiaceae – Pavetteae), With Description of Thirteen New Species”. European Journal of Taxonomy 801, no. 1 (March 10, 2022): 1–99. Accessed April 25, 2024. https://europeanjournaloftaxonomy.eu/index.php/ejt/article/view/1685.