United States. Bureau of Labor Statistics. "April 1971," CPI Detailed Report (April 1971). https://fraser.stlouisfed.org/title/58/item/22173, accessed on April 19, 2024.
United States. Bureau of Labor Statistics. "April 1971," CPI Detailed Report (April 1971). https://fraser.stlouisfed.org/title/58/item/22173, accessed on April 19, 2024.