United States. Bureau of Economic Analysis. "June 1928," Survey of Current Business (June 1928). https://fraser.stlouisfed.org/title/46/item/9226, accessed on December 10, 2023.
United States. Bureau of Economic Analysis. "June 1928," Survey of Current Business (June 1928). https://fraser.stlouisfed.org/title/46/item/9226, accessed on December 10, 2023.