Federal Reserve Bank of Chicago. "May 1, 1940, Volume 23, Number 4," Business Conditions (Federal Reserve Bank of Chicago) (May 1, 1940). https://fraser.stlouisfed.org/title/5562/item/539927, accessed on May 14, 2024.
Federal Reserve Bank of Chicago. "May 1, 1940, Volume 23, Number 4," Business Conditions (Federal Reserve Bank of Chicago) (May 1, 1940). https://fraser.stlouisfed.org/title/5562/item/539927, accessed on May 14, 2024.