Federal Reserve Bank of Chicago. "April 1970," Business Conditions (Federal Reserve Bank of Chicago) (April 1970). https://fraser.stlouisfed.org/title/5562/item/540286, accessed on April 25, 2024.
Federal Reserve Bank of Chicago. "April 1970," Business Conditions (Federal Reserve Bank of Chicago) (April 1970). https://fraser.stlouisfed.org/title/5562/item/540286, accessed on April 25, 2024.