00306nam a2200109 a 450000500170000002000150001708200230003210000360005524500500009126000360014130000190017720251203091726.0  a0851986714  a589.90133,bD, GIL  aGiller, Ken E., Wilson, Kate J.  aNitrogen fixation in tropical cropping system  aOxonbC.A.B.Internationalc1991  axii,314p, 22cm