00281nam a2200109Ia 450000500170000000800410001708200170005810000200007524500320009526000360012730000080016320260224040941.0260224s9999||||xx |||||||||||||| ||und||  a581.1333 DIX  aDixon,. R.O.D.  0aNitrogen fixation in plants  aNew York: Chapman & Hall,c1986  a157