Worldwatch
Worldwatch paper [elektronický zdroj]. -- 1 (1975)-172 (2006). -- Washington, D.C. : Worldwatch Institute, 1975-2006. -- 172 v. : ill., maps ; 22 cm. -- Last issue consulted: 172, published in Nov. 2006.
Worldwatch Institute
Human ecology.. Conservation of natural resources.. Energy conservation.. Power resources. Écologie humaine - Collections.. Conservation des ressources naturelles - Collections.. Économies d'énergie - Collections.. Ressources énergétiques - Collections