Labor violence and the Hobbs Act : hearings before the Committee on the Judiciary, United States Senate, Ninety-eighth Congress, first and second sessions, on S. 462 a bill to amend Section 1951 of Title 18 of the United States Code, and for other purposes, October 25, 1983 ; April 30 and May 1, 1984. (U.S. G.P.O., 1984)