United Nations Economic Commission for Europe. (1979). The Gas Situation in the ECE Region Around the Year 1990. ELSEVIER.
Chicago-referens (17:e uppl.)United Nations Economic Commission for Europe. The Gas Situation in the ECE Region Around the Year 1990. ELSEVIER, 1979.
MLA-referens (8:e uppl.)United Nations Economic Commission for Europe. The Gas Situation in the ECE Region Around the Year 1990. ELSEVIER, 1979.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.