Federal Reserve Bank of Chicago. "May 1967," Business Conditions (Federal Reserve Bank of Chicago) (May 1967). https://fraser.stlouisfed.org/title/5562/item/540251, accessed on May 7, 2024.
Federal Reserve Bank of Chicago. "May 1967," Business Conditions (Federal Reserve Bank of Chicago) (May 1967). https://fraser.stlouisfed.org/title/5562/item/540251, accessed on May 7, 2024.