00421nam a2200169 a 450000100080000000500110000800800410001902000180006010000190007824500440009726000370014130000110017865000160018965000130020565000180021870000150023612386802006-12-11       1975    bl uuuu      00u1 u    #d  a0-300-01815-01 aEVENSON, R. E.  aAgricultural research and productivity.  aNew Haven: Yale Universityc1975  a204 p.  aAgricultura  aPesquisa  aProdutividade1 aKISKEV, Y.