United States. Bureau of Economic Analysis. "Pollution Abatement and Control Accounted for 1.6 Percent of Total U.S. Output in 1972, Major New Study Shows, BEA 75-14,"
Bureau of Economic Analysis (BEA) News Releases
(March 4, 1975).
https://fraser.stlouisfed.org/title/6148/item/595432, accessed on March 22, 2025.
@FedFRASER