United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "August 1984," PPI Detailed Report (August 1984) : 158-158. https://fraser.stlouisfed.org/title/63/item/21585/toc/220407 , accessed on April 19, 2024.
United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "August 1984," PPI Detailed Report (August 1984) : 158-158. https://fraser.stlouisfed.org/title/63/item/21585/toc/220407 , accessed on April 19, 2024.