United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "August 1982," PPI Detailed Report (August 1982) : 106-106. https://fraser.stlouisfed.org/title/63/item/21561/toc/218048 , accessed on March 28, 2024.
United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "August 1982," PPI Detailed Report (August 1982) : 106-106. https://fraser.stlouisfed.org/title/63/item/21561/toc/218048 , accessed on March 28, 2024.