United States. Bureau of Economic Analysis. "March 1940," Survey of Current Business (March 1940). https://fraser.stlouisfed.org/title/46/item/9366, accessed on June 21, 2024.
United States. Bureau of Economic Analysis. "March 1940," Survey of Current Business (March 1940). https://fraser.stlouisfed.org/title/46/item/9366, accessed on June 21, 2024.