Rodrigues, Sónia Sofia S., Carla Sofia S. Ferreira, et Paulo C. Silveira. 2005. « An historical survey of the botanical research done at the Lousã mountain system (Portugal) ». Botanica Complutensis 29 (juin): 35-42. https://revistas.ucm.es/index.php/BOCM/article/view/BOCM0505110035A.