Physical description for original version: 40 p. : 28 cm
書誌注記
Includes bibliographical references (p. 16)
原資料等に関する注記
原資料の出版事項: Fort Collins, Colo. (240 W. Prospect St., Fort Collins 80526) : U.S. Dept. of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, [1990]