Federal Reserve Bank of Chicago. "May 1961," Business Conditions (Federal Reserve Bank of Chicago) (May 1961). https://fraser.stlouisfed.org/title/5562/item/540179, accessed on April 24, 2024.
Federal Reserve Bank of Chicago. "May 1961," Business Conditions (Federal Reserve Bank of Chicago) (May 1961). https://fraser.stlouisfed.org/title/5562/item/540179, accessed on April 24, 2024.