United States. Bureau of Labor Statistics. "Price Movements," in United States. Bureau of Labor Statistics. "May 1987," PPI Detailed Report (May 1987) : 5-7. https://fraser.stlouisfed.org/title/63/item/21618/toc/132852 , accessed on April 23, 2024.
United States. Bureau of Labor Statistics. "Price Movements," in United States. Bureau of Labor Statistics. "May 1987," PPI Detailed Report (May 1987) : 5-7. https://fraser.stlouisfed.org/title/63/item/21618/toc/132852 , accessed on April 23, 2024.