United States. Bureau of Labor Statistics. "Charts," in United States. Bureau of Labor Statistics. "September 1999," PPI Detailed Report (September 1999) : 9-11. https://fraser.stlouisfed.org/title/63/item/21769/toc/295984 , accessed on May 2, 2024.
United States. Bureau of Labor Statistics. "Charts," in United States. Bureau of Labor Statistics. "September 1999," PPI Detailed Report (September 1999) : 9-11. https://fraser.stlouisfed.org/title/63/item/21769/toc/295984 , accessed on May 2, 2024.