Separation of powers : Hearings before the Subcommittee on Separation of Powers of the Committee on the Judiciary, United States Senate, Ninetieth Congress, first session, a study of the separation of powers between the executive, judicial, and legislative branches of government provided by the constitution, the manner in which power has been exercised by each branch and the extent, if any, to which any branch or branches of the government may have encroached upon the powers, functions, and duties vested in any other branch by the constitution of the United States.