Physical description for original version: iv, 42 p. : 28 cm
書誌注記
Includes bibliographical references (p. 32-34)
原資料等に関する注記
原資料の出版事項: Washington, DC ; Rockville, MD : U.S. Dept. of Agriculture, Economic Research Service, Agriculture and Trade Analysis Division : ERS-NASS, distributor, [1991]