United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "July 1981," PPI Detailed Report (July 1981) : 3-3. https://fraser.stlouisfed.org/title/63/item/21548/toc/401637 , accessed on April 25, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "July 1981," PPI Detailed Report (July 1981) : 3-3. https://fraser.stlouisfed.org/title/63/item/21548/toc/401637 , accessed on April 25, 2024.