Extension of purchase programs of strategic and critical minerals : Hearings before the Subcommittee on Minerals, Materials, and Fuels of the Committee on Interior and Insular Affairs, United States Senate, Eighty-fourth Congress, second session, on S. 2876 [and other] bills to encourage the discovery, development, and production of tungsten, manganese, chromite, mica, asbestos, beryl, columbium-tantalumbearing ore or concentrate, antimony, mercury, and flourspar in the United States, its territories, and possessions --