Não informado. (1980). Enhanced Energy Recovery News. Business Communications.
Chicago-referens (17:e uppl.)Não informado. Enhanced Energy Recovery News. Houston, Tex: Business Communications, 1980.
MLA-referens (8:e uppl.)Não informado. Enhanced Energy Recovery News. Business Communications, 1980.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.