United States. Bureau of Labor Statistics. "Coal," in United States. Bureau of Labor Statistics. "November 1984," PPI Detailed Report (November 1984) : 13-13. https://fraser.stlouisfed.org/title/63/item/21588/toc/120529 , accessed on March 29, 2024.
United States. Bureau of Labor Statistics. "Coal," in United States. Bureau of Labor Statistics. "November 1984," PPI Detailed Report (November 1984) : 13-13. https://fraser.stlouisfed.org/title/63/item/21588/toc/120529 , accessed on March 29, 2024.