00263nam a2200085Ia 4500008004100000100002700041245006100068260004000129300000800169140113s9999    xx            000 0 und d  a"Stewart, W.D.P., Ed."  aNitrogen fixation by free living micro-organisms (IBP 6)  a1975bCambridge Univ. PresscLondon  a471