Federal Reserve Bank of Chicago. "September 1961," Business Conditions (Federal Reserve Bank of Chicago) (September 1961). https://fraser.stlouisfed.org/title/5562/item/540183, accessed on March 28, 2024.
Federal Reserve Bank of Chicago. "September 1961," Business Conditions (Federal Reserve Bank of Chicago) (September 1961). https://fraser.stlouisfed.org/title/5562/item/540183, accessed on March 28, 2024.