00319nam a2200109Ia 4500008004100000082002100041100002000062245004100082260003000123490003400153650002200187220204s9999    xx            000 0 und d  a631.461.5bSPR;1  aSPRENT, Janet I 0aBiology of nitrogen fixing organisms  aLondonbMcGraw hillc1979  aEuropean plant biology series  aNitrogen fixation