Physical description for original version: iii, 74 p. ; 28 cm
原資料等に関する注記
原資料の出版事項: [Reston, Va.?] ; Denver, CO (Federal Center, Box 25425, Denver 80225) : U.S. Dept. of the Interior, U.S. Geological Survey : For sale by Book and Open-File Report Sales, 1992