United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "January 1990," PPI Detailed Report (January 1990) : 3-4. https://fraser.stlouisfed.org/title/63/item/21653/toc/329106 , accessed on April 23, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "January 1990," PPI Detailed Report (January 1990) : 3-4. https://fraser.stlouisfed.org/title/63/item/21653/toc/329106 , accessed on April 23, 2024.