United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "May 1983," PPI Detailed Report (May 1983) : 119-119. https://fraser.stlouisfed.org/title/63/item/21570/toc/268035 , accessed on April 18, 2024.
United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "May 1983," PPI Detailed Report (May 1983) : 119-119. https://fraser.stlouisfed.org/title/63/item/21570/toc/268035 , accessed on April 18, 2024.