Ahmed, Osumanu Haruna, <br/><br/>
Humic substances and urea :  use in agriculture / 
Ahmed Osumanu Haruna. 
 - 169 pages :  charts, illustrations ;  25 cm. 
<br/><br/><label>ISBN: </label>9789673444069  RM40.50 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Humic acid.<br/>Organic fertilizers.<br/>Soils--Composition.