Department of the Interior and related agencies appropriations for 1973. Part 1, Bureau of Mines; Federal Metal and Nonmetallic Mine Safety Board of Review; Geological Survey; Office of Coal Research; Office of Oil and Gas; Office of the Solicitor; Office of Water Resources Research; Secretary of the Interior : hearings before a subcommittee of the Committee on Appropriations, House of Representatives, Ninety-second Congress, second session / Subcommittee on Department of the Interior and Related Agencies