Physical description for original version: iv, 69 p. : 29 cm
書誌注記
Includes bibliographical references (p. 59-63)
原資料等に関する注記
原資料の出版事項: [Reston, Va.?] ; Denver, CO : Dept. of the Interior, U.S. Geological Survey : For sale by the Books and Open-File Reports Section, 1988 [i.e. 1989]