00394nam a2200133Ia 4500008004100000082001700041100001900058245005100077260002100128300001300149600003700162600002100199650004000220140224s9999    xx            000 0 und d  a581.138.1 N1  aGiller, Ken E.  aNitrogen fixation in tropical cropping systems  aOxonbCABIc1991  axi,313p.  a Ken E.Giller and Kate J.Wilson.  aWilson, Kate, J.  aNitrogen fixation,Cropping systems.