Public Law 75-314 / Chapter 690, 75 Congress, Session 1, An act: to provide additional revenue for the District of Columbia, and for other purposes -- Public Law 75-519 / Chapter 223, 75 Congress, Session 3, An act: to amend the District of Columbia Revenue Act of 1937, and for other purposes -- Public Law 76-225 / Chapter 367, 76 Congress, Session 1, An act: to provide revenue for the District of Columbia, and for other purposes -- Public Law 77-428 / Chapter 33, 77 Congress, Session 2, An act: to amend the District of Columbia Revenue Act of 1939, and for other purposes -- Public Law 77-621 / Chapter 433, 77 Congress, Session 2, An act: to amend the District of Columbia Income Tax Act, as amended, and for other purposes