Reorganization Plan No. 4 of 1966 : National Zoological Park: hearings before the United States House Committee on Government Operations, Subcommittee on Executive and Legislative Reorganization, Eighty-Ninth Congress, second session, on Aug. 9, 1966.

Considers plan to transfer to the Smithsonian Institution, from the D.C. Board of Commissioners, responsibility for preparing building plans at the National Zoo.