Collings, Gilbert H. <br/><br/>
Commercial fertilizers : their sources and use 
Gilbert H. Collings 
 - 5th ed. 
 - Bombay  Tata-McGraw-Hill  1962 
 - xi, 617p.: ill.; 23cm. 
<br/><br/><label>Dewey Class. No.: </label>581.61  / COL