Federal Reserve Bank of Philadelphia. "January 1968," Business Review (Federal Reserve Bank of Philadelphia) (January 1968). https://fraser.stlouisfed.org/title/5580/item/557472, accessed on April 18, 2024.
Federal Reserve Bank of Philadelphia. "January 1968," Business Review (Federal Reserve Bank of Philadelphia) (January 1968). https://fraser.stlouisfed.org/title/5580/item/557472, accessed on April 18, 2024.