Hopkins, Donald Percy,  1909- <br/><br/>
Chemicals, humus, and the soil;  a simple presentation of contemporary knowledge and opinions about fertilizers, manures, and soil fertility. 

 - [American ed.] 
 - Brooklyn,  Chemical Pub. Co.,  1948. 
 - viii, 358 p.  illus.  21 cm. 
<br/><br/>Bibliography: p. 347-349. 
<br/><br/><label>LCCN: </label>agr48000213  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Fertilizers.<br/>Manures.<br/>Humus.<br/>Soil fertility.
<br/><br/><label>LC Class. No.: </label>S633  / .H76 1948