Utilization of the azolla-anabaena complex as a nitrogen fertilizer for rice / 
I. Watanabe ... [et al.]. 
 - Manila, Philippines :  The International Rice Research Institute,  1977. 
 - 15 p. :  ill. 
 - IRRI research paper series ;  no. 11 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Azolla as fertilizer.<br/>Rice--Fertilizers.<br/>Nitrogen fertilizers.