United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "June 1989," PPI Detailed Report (June 1989) : 3-4. https://fraser.stlouisfed.org/title/63/item/21646/toc/366024 , accessed on May 12, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "June 1989," PPI Detailed Report (June 1989) : 3-4. https://fraser.stlouisfed.org/title/63/item/21646/toc/366024 , accessed on May 12, 2024.