First Quarter 1971
United States. Bureau of Labor Statistics. "First Quarter 1971," Productivity and Costs (April 23, 1971). https://fraser.stlouisfed.org/title/131/item/55848, accessed on April 17, 2024.
United States. Bureau of Labor Statistics. "First Quarter 1971," Productivity and Costs (April 23, 1971). https://fraser.stlouisfed.org/title/131/item/55848, accessed on April 17, 2024.