Martin Polo, J., Valle Gutierrez, C., Blanco de Pablos, A. and Sánchez Rodríguez, M. (2003) “Forages resources in "dehesa" system: fertilization, tillage and forage sowing. I. Influence to the environment (soil and vegetation)”, Spanish Journal of Agricultural Research, 1(1), pp. 23-33. doi: 10.5424/sjar/2003011-6.