http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CEsQFjAD&url=http%3A%2F%2Fdspace.univ-tlemcen.dz%2Fbitstream%2F112%2F240%2F1%2FTypologieCartographieDesStationsForestieresEtModelisationsDesPeuplementsForestiers-CasDesMassifsForestiersDeLaWilayadeSaida%28Algerie%29.pdf&ei=AnFgUengDYK9rQHzuYH4Bg&usg=AFQjCNGDxHhb1ghvoTrOAbclYc1bbhQI_A&sig2=gKHBx-DpCNKtJzbcKU3hOA