000 00267nam a2200097Ia 4500
100 _aBergersen F J Ed
245 _aMethods for Evaluating Biological Nitrogen Fixation
260 _bJohn Wiley & Sons, New York
082 _aJ:1:41/N80/B14489
300 _app 702; 23*15
999 _c35214
_d35214