APA
United Nations Economic Commission for Europe, United Nations Economic Commission for Europe, . (1991). Sustainable energy developments in Europe and Nort. Geneva: United Nations.
Chicago
United Nations Economic Commission for Europe, United Nations Economic Commission for Europe, . 1991. Sustainable energy developments in Europe and Nort. Geneva: United Nations.
Harvard
United Nations Economic Commission for Europe, United Nations Economic Commission for Europe, . (1991). Sustainable energy developments in Europe and Nort. Geneva: United Nations.
MLA
United Nations Economic Commission for Europe, United Nations Economic Commission for Europe, . Sustainable energy developments in Europe and Nort. Geneva: United Nations. 1991.