AEC authorizing legislation, fiscal year 1972. Part 4, March 18, 23, and May 13, 1971 : hearings before the Joint Committee on Atomic Energy, Congress of the United States, Ninety-second Congress, first session on nuclear materials; peaceful uses of atomic energy (Plowshare); weapons; biology and medicine; training, education, and information; isotopes development; community; regulation; program direction and administration; security investigations; and amendments to the AEC authorization bill