00443nam a2200157Ia 4500008004100000020001500041082002000056100001600076245006600092260004000158300000800198650002300206650001800229653002200247700001600269170901s1977    xx            000 0 und d  a0471994995  a589.70913bA95B  aAyanaba, A. 0aBiological Nitogen Fixation in Farming Systems of the Tropics  aNew YorkbJohn Wiley and Sonsc1977  a377  aBotanical sciences  aPure Sciences  aNitrogen fixation  aDart, P. J.