United States. Bureau of Economic Analysis. "January 1968," Survey of Current Business (January 1968). https://fraser.stlouisfed.org/title/46/item/9749, accessed on April 20, 2024.
United States. Bureau of Economic Analysis. "January 1968," Survey of Current Business (January 1968). https://fraser.stlouisfed.org/title/46/item/9749, accessed on April 20, 2024.