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

 - London :  Faber and Faber,  1945 
 - 278 p.  : ilus. 
<br/><br/><label>LCCN: </label>16455 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Fertilizantes y abonos.<br/>Humus.
<br/><br/><label>Dewey Class. No.: </label>631.8  / H66