Pardini, G., R. Aringhieri, F. Plana, y F. Gallart. 1991. «Soil Properties Relevant to Land Degradation in Abandoned Sloping Fields in Aisa Valley, Central Pyrenees (Spain)». Pirineos 137 (junio):95-109. https://doi.org/10.3989/pirineos.1991.v137.196.