United States. Bureau of Economic Analysis. "February 1931," Survey of Current Business (February 1931). https://fraser.stlouisfed.org/title/46/item/9258, accessed on April 18, 2024.
United States. Bureau of Economic Analysis. "February 1931," Survey of Current Business (February 1931). https://fraser.stlouisfed.org/title/46/item/9258, accessed on April 18, 2024.