Costanzo, Emanuele, et al. «A phytosociological survey of the main plant community types of alpine and sub-alpine belt in the Sibillini Mountains (Central Apennines, Italy)». Lazaroa, vol. 30, febrero de 2010, pp. 219-50, https://revistas.ucm.es/index.php/LAZA/article/view/LAZA0909110219A.