Hopkins, Donald P. <br/><br/>
Chemicals, humus and the soil; a a simple presentation of contemporary knowledge and opinions about fertilizers, manures and soil fertility 

 - Brooklyn :  Chemical Pub.,  1948 
 - 358 p. 
<br/><br/><label>LCCN: </label>16456 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Fertilizantes y abonos.<br/>Humus.
<br/><br/><label>Dewey Class. No.: </label>631.8  / H66 1948