United States. Bureau of Economic Analysis. "February 1968," Survey of Current Business (February 1968). https://fraser.stlouisfed.org/title/46/item/9750, accessed on May 9, 2024.
United States. Bureau of Economic Analysis. "February 1968," Survey of Current Business (February 1968). https://fraser.stlouisfed.org/title/46/item/9750, accessed on May 9, 2024.