Collings, Gilbeart H. <br/><br/>
Commercial fertilizers:  their sources and use/ 
by Gilbeart H. Collings 
 - 5th ed. 
 - New York:  McGraw-Hill,  1955 
 - xi, 617p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Fertilizers