United States. Bureau of Economic Analysis. "September 2011," Survey of Current Business (September 2011). https://fraser.stlouisfed.org/title/46/item/10230, accessed on May 8, 2024.
United States. Bureau of Economic Analysis. "September 2011," Survey of Current Business (September 2011). https://fraser.stlouisfed.org/title/46/item/10230, accessed on May 8, 2024.