United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "December 1988," PPI Detailed Report (December 1988) : 3-3. https://fraser.stlouisfed.org/title/63/item/21637/toc/231912 , accessed on May 5, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "December 1988," PPI Detailed Report (December 1988) : 3-3. https://fraser.stlouisfed.org/title/63/item/21637/toc/231912 , accessed on May 5, 2024.