Não informado. (1966). Air Pollution Titles. Pennsylvania State University, Center for Air Environmental Studies.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Air Pollution Titles. University Park, Pa: Pennsylvania State University, Center for Air Environmental Studies, 1966.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Air Pollution Titles. Pennsylvania State University, Center for Air Environmental Studies, 1966.
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