United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "May 1982," PPI Detailed Report (May 1982) : 98-98. https://fraser.stlouisfed.org/title/63/item/21558/toc/243414 , accessed on March 29, 2024.
United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "May 1982," PPI Detailed Report (May 1982) : 98-98. https://fraser.stlouisfed.org/title/63/item/21558/toc/243414 , accessed on March 29, 2024.