United States Environmental Protection Agency. (1971). The economics of clean air: Report of the administrator of the Environmental Protection Agency to the Congress of the United States in compliance with Public Law 90-148, the Clean Air Act, as amended, March 1971. U.S. Government Printing Office.
Παραπομπή σε μορφή Chicago (17η εκδ.)United States Environmental Protection Agency. The Economics of Clean Air: Report of the Administrator of the Environmental Protection Agency to the Congress of the United States in Compliance with Public Law 90-148, the Clean Air Act, as Amended, March 1971. Washington: U.S. Government Printing Office, 1971.
Παραπομπή σε μορφή MLA (9th εκδ.)United States Environmental Protection Agency. The Economics of Clean Air: Report of the Administrator of the Environmental Protection Agency to the Congress of the United States in Compliance with Public Law 90-148, the Clean Air Act, as Amended, March 1971. U.S. Government Printing Office, 1971.