00454nam a22001817a 4500003000500000005001700005008004100022010001000063011001000073035001000083040000900093082001600102100002400118245004600142260003300188300001100221650004000232CHAP20220817041540.0971013s1953            r     00010     d  a17697  a18669  a22754  cCHAP  a338.1bB62i00aBlack, John Donald.  aIntroduction to economics for agriculture  aNew York :bMacNillan,c1953  a727 p.14aAgriculturaxAspectos económicos.