United States. Bureau of Labor Statistics. "April 1971," The Employment Situation (May 7, 1971). https://fraser.stlouisfed.org/title/144/item/496971, accessed on April 19, 2024.
United States. Bureau of Labor Statistics. "April 1971," The Employment Situation (May 7, 1971). https://fraser.stlouisfed.org/title/144/item/496971, accessed on April 19, 2024.