United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "June 1983," PPI Detailed Report (June 1983) : 118-118. https://fraser.stlouisfed.org/title/63/item/21571/toc/175250 , accessed on March 28, 2024.
United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "June 1983," PPI Detailed Report (June 1983) : 118-118. https://fraser.stlouisfed.org/title/63/item/21571/toc/175250 , accessed on March 28, 2024.