=LDR 22 4500 =001 1821 =082 04$a630 DUC =100 1\$aDuckham, A. N. =245 10$aFarming systems of the world =260 \\$aLondon :$bChatto and Windus,$c1971 =650 \0$aBooks =700 1\$aMasefield, G. B. =852 \\$bFreeman Library$h630 DUC$zNot located