United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "March 1984," PPI Detailed Report (March 1984) : 143-143. https://fraser.stlouisfed.org/title/63/item/21580/toc/207551 , accessed on March 29, 2024.
United States. Bureau of Labor Statistics. "Mining," in United States. Bureau of Labor Statistics. "March 1984," PPI Detailed Report (March 1984) : 143-143. https://fraser.stlouisfed.org/title/63/item/21580/toc/207551 , accessed on March 29, 2024.