Hearings Before the United States Senate Committee of the Judiciary, Subcommittee on Antitrust and Monopoly, Eighty-Fifth Congress, Second Session, Eighty-Sixth Congress, First Session, Eighty-Sixth Congress, Second Session, Eighty-Eighth Congress, First Session, Eighty-Ninth Congress, First Session, Ninetieth Congress, Second Session, Ninety-First Congress, First Session