Environmental impact of human activities on water resources and its characterization for management and planning of natural areas 'las batuecas-sierra francia' and 'quilamas' (Salamanca, Spain)

1. Martínez-Graña, A.M.
2. Goy Goy, J.L.
3. de Bustamante Gutiérrez, I.
4. Zazo Cardeña, C.