Federal Reserve Bank of Dallas. "Amendment to Regulation T, Circular No. 81-201," District Notices (Federal Reserve Bank of Dallas) (October 22, 1981). https://fraser.stlouisfed.org/title/5569/item/541383, accessed on November 17, 2018.
Regulation T, Credit by Brokers and Dealers. Amended Effective 10-26-81, to Establish Margin Requirement for Options on Exempted Debt Securities.