United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "October 1991," PPI Detailed Report (October 1991) : 3-4. https://fraser.stlouisfed.org/title/63/item/21672/toc/112787 , accessed on April 24, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "October 1991," PPI Detailed Report (October 1991) : 3-4. https://fraser.stlouisfed.org/title/63/item/21672/toc/112787 , accessed on April 24, 2024.