Duck stamp design : hearing before the Subcommittee on Fisheries and Wildlife Conservation and the Environment of the Committee on Merchant Marine and Fisheries, House of Representatives, Ninety-ninth Congress, second session, on H.R. 3149 a bill relating to the conduct of public contests for the purpose of selecting the design of duck hunting stamps, and for other purposes, May 14, 1986. (U.S. G.P.O., 1986)