United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "January 1981," PPI Detailed Report (January 1981) : 3-3. https://fraser.stlouisfed.org/title/63/item/21542/toc/77789 , accessed on April 24, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "January 1981," PPI Detailed Report (January 1981) : 3-3. https://fraser.stlouisfed.org/title/63/item/21542/toc/77789 , accessed on April 24, 2024.