Federal Reserve Bank of Chicago. "February 1968," Business Conditions (Federal Reserve Bank of Chicago) (February 1968). https://fraser.stlouisfed.org/title/5562/item/540260, accessed on April 25, 2024.
Federal Reserve Bank of Chicago. "February 1968," Business Conditions (Federal Reserve Bank of Chicago) (February 1968). https://fraser.stlouisfed.org/title/5562/item/540260, accessed on April 25, 2024.