Federal Reserve Bank of Chicago. "March 1971," Business Conditions (Federal Reserve Bank of Chicago) (March 1971). https://fraser.stlouisfed.org/title/5562/item/540297, accessed on April 24, 2024.
Federal Reserve Bank of Chicago. "March 1971," Business Conditions (Federal Reserve Bank of Chicago) (March 1971). https://fraser.stlouisfed.org/title/5562/item/540297, accessed on April 24, 2024.