United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "April 1998," PPI Detailed Report (April 1998) : 3-4. https://fraser.stlouisfed.org/title/63/item/21750/toc/122496 , accessed on March 28, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "April 1998," PPI Detailed Report (April 1998) : 3-4. https://fraser.stlouisfed.org/title/63/item/21750/toc/122496 , accessed on March 28, 2024.