Federal Reserve Bank of Chicago. "December 1967," Business Conditions (Federal Reserve Bank of Chicago) (December 1967). https://fraser.stlouisfed.org/title/5562/item/540258, accessed on March 29, 2024.
Federal Reserve Bank of Chicago. "December 1967," Business Conditions (Federal Reserve Bank of Chicago) (December 1967). https://fraser.stlouisfed.org/title/5562/item/540258, accessed on March 29, 2024.