Symbiotic Nitrogen Fixation in Plants 

 - Cambridge :   Cambridge University Press,  1976  
 - International Biological Programme 7 .
<br/><br/><label>ISBN: </label>0521206456 
<br/><br/><label>Standard No.: </label>DEX-M6638 
<br/><br/><label>Universal Decimal Class. No.: </label>631.416.1