(1957). Long Range Minerals Program. hearings before the United States Senate Committee on Interior and Insular Affairs, Subcommittee on Minerals, Materials, and Fuels, Eighty-Fifth Congress, first session, on July 29, 31, Aug. 28, 1957. [electronic resource]: Part 2.
Lua i Stíl Chicago (17ú heag.)Long Range Minerals Program. Hearings Before the United States Senate Committee on Interior and Insular Affairs, Subcommittee on Minerals, Materials, and Fuels, Eighty-Fifth Congress, First Session, on July 29, 31, Aug. 28, 1957. [electronic Resource]: Part 2. 1957.
Lua MLA (9ú heag.)Long Range Minerals Program. Hearings Before the United States Senate Committee on Interior and Insular Affairs, Subcommittee on Minerals, Materials, and Fuels, Eighty-Fifth Congress, First Session, on July 29, 31, Aug. 28, 1957. [electronic Resource]: Part 2. 1957.