United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "April 1978," Business Conditions Digest (April 1978) : 65-65. https://fraser.stlouisfed.org/title/43/item/7380/toc/204536 , accessed on May 1, 2024.
United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "April 1978," Business Conditions Digest (April 1978) : 65-65. https://fraser.stlouisfed.org/title/43/item/7380/toc/204536 , accessed on May 1, 2024.