United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "June 1981," PPI Detailed Report (June 1981) : 3-3. https://fraser.stlouisfed.org/title/63/item/21547/toc/94165 , accessed on April 18, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "June 1981," PPI Detailed Report (June 1981) : 3-3. https://fraser.stlouisfed.org/title/63/item/21547/toc/94165 , accessed on April 18, 2024.