00345nam a2200145 a 450000100080000000500110000800800410001910000230006024500230008326000280010630000090013465300100014365300240015370000220017711155882000-10-11       1977    bl uuuu     u0uu1 u    #d1 aSILVEIRA, D.R. da.  aO arado de discos.  aSanta Maria: UFSMc1977  a25p.  aARADO  aENGENHARIA AGRICOLA1 aSOUZA, L.F.C. de.