00326nam a2200121Ia 4500001000500000005001700005008004100022082001400063100001900077245007400096260001800170650001600188366820261006003724.0120911s9999    xx            000 0 und d  a388.1 HEA  aHeady, Earl O.  aEconomics of agricultural production and resource use / Earl O. Heady  aPrentice Hall  aAgriculture