Não informado. (1966). Air Pollution Titles. Pennsylvania State University, Center for Air Environmental Studies.
Chicago-referens (17:e uppl.)Não informado. Air Pollution Titles. University Park, Pa: Pennsylvania State University, Center for Air Environmental Studies, 1966.
MLA-referens (8:e uppl.)Não informado. Air Pollution Titles. Pennsylvania State University, Center for Air Environmental Studies, 1966.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.