. . . . . . . . . "The investigation of the effectiveness of the Hobbs amendment in suppressing racketeering : hearings before a subcommittee of the Committee on Expenditures in the Executive Departments, House of Representatives, Eightieth Congress, first session. February 14, [M]arch 6, 10, 13, 14, 19, and 20, 1947" . . . . . .