Collings, Gilbeard H. <br/><br/>
Commercial fertilizers:  their sources and use / 
Gilbeart H. Collings 
 - Philadelphia :  Blakiston ,  1941 
 - xx, 480 p. :  ill. ;  23 cm. 
<br/><br/><label>ISBN: </label> Rs. 4.50 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Fertilizers