Elena, R., F. Sánchez, A. Rubio, V. Gómez, A. Aunós, A. Blanco, and O. Sánchez. “Autoecology of Beech Woodstands in Catalonia (Spain)”. Forest Systems, Vol. 10, no. 1, June 2001, pp. 21-42, doi:10.5424/709.