United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "January 1987," PPI Detailed Report (January 1987) : 3-3. https://fraser.stlouisfed.org/title/63/item/21614/toc/177629 , accessed on April 19, 2024.
United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "January 1987," PPI Detailed Report (January 1987) : 3-3. https://fraser.stlouisfed.org/title/63/item/21614/toc/177629 , accessed on April 19, 2024.