Source: https://www.researchgate.net/profile/Nzoussi-Kevin/publication/293648177_LA_GESTION_DE_L'ENVIRONNEMENT_URBAIN_A_BRAZZAVILLE_PROBLEMES_ET_PERSPECTIVES/links/56ba131d08ae3a9ac4365845/LA-GESTION-DE-LENVIRONNEMENT-URBAIN-A-BRAZZAVILLE-PROBLEMES-ET-PERSPECTIVES.pdf