United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "June 1987," PPI Detailed Report (June 1987) : 3-3. https://fraser.stlouisfed.org/title/63/item/21619/toc/45769 , accessed on May 4, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "June 1987," PPI Detailed Report (June 1987) : 3-3. https://fraser.stlouisfed.org/title/63/item/21619/toc/45769 , accessed on May 4, 2024.