Federal Reserve Bank of Chicago. "January 1940, Volume 23, Number 1," Business Conditions (Federal Reserve Bank of Chicago) (January 1940). https://fraser.stlouisfed.org/title/5562/item/539924, accessed on May 21, 2024.
Federal Reserve Bank of Chicago. "January 1940, Volume 23, Number 1," Business Conditions (Federal Reserve Bank of Chicago) (January 1940). https://fraser.stlouisfed.org/title/5562/item/539924, accessed on May 21, 2024.