00408nam a2200145   450000500170000000700040001700800040002104000090002505000220003424500610005626000680011730000220018550000190020765000360022620150626085952.0000000  aUOEL  aS21.A35b.Y4 1970  aContours of Change :bThe yearbook of Agriculture 1970 /  aWashington ;bUnited States Department of Agriculture ,cc1970.  axL, 366p. :bill.  aIncludes index  2Contours of changexAgriculture