Carter, Vernon Gill. <br/><br/>
Topsoil and civilization 

 - Norman, Okla. :  University of Oklahoma,  1974 
 - 292 p.  : láms. 
<br/><br/><label>LCCN: </label>12520 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Recursos naturales--Conservación.<br/>Suelos--Conservación--Historia.
<br/><br/><label>Dewey Class. No.: </label>631.45  / C3