Federal Reserve Bank of Chicago. "September 1971," Business Conditions (Federal Reserve Bank of Chicago) (September 1971). https://fraser.stlouisfed.org/title/5562/item/540303, accessed on May 3, 2024.
Federal Reserve Bank of Chicago. "September 1971," Business Conditions (Federal Reserve Bank of Chicago) (September 1971). https://fraser.stlouisfed.org/title/5562/item/540303, accessed on May 3, 2024.