Federal Reserve Bank of Dallas. "Check Digit Implementation on July 1, 1978, Circular No. 78-75," District Notices (Federal Reserve Bank of Dallas) (June 8, 1978). https://fraser.stlouisfed.org/title/5569/item/542484, accessed on April 23, 2024.
Federal Reserve Bank of Dallas. "Check Digit Implementation on July 1, 1978, Circular No. 78-75," District Notices (Federal Reserve Bank of Dallas) (June 8, 1978). https://fraser.stlouisfed.org/title/5569/item/542484, accessed on April 23, 2024.