United States. Bureau of Economic Analysis. "March 1971," Survey of Current Business (March 1971). https://fraser.stlouisfed.org/title/46/item/9803, accessed on May 11, 2024.
United States. Bureau of Economic Analysis. "March 1971," Survey of Current Business (March 1971). https://fraser.stlouisfed.org/title/46/item/9803, accessed on May 11, 2024.