Juvenile delinquency : hearings before the Subcommittee to Investigate Juvenile Delinquency of the Committee on the Judiciary, United States Senate, Ninety-second Congress, first session, pursuant to S. Res. 342 [i.e. 32] section 12, investigation of juvenile delinquency in the United States : the role of the federal government in the area of juvenile delinquency, March 31 and April 1, 1971