Twenhofel, William H.  1875-1957. <br/><br/>
Soil, the most valuable mineral resource,  its origin, destruction and preservation, 
by W. H. Twenhofel. 
 - [Portland,  1944] 
 - 45, [2] p.  illus., plates.  28 cm. 
 - Oregon. State Dept. of Geology and Mineral Industries. Bulletin  no. 26 .
<br/><br/> Reproduced from type-written copy. 
<br/><br/>"References cited": p. [46]-[47] 
<br/><br/><label>LCCN: </label>gs 44000046  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Erosion.<br/>Soil conservation.
<br/><br/><label>LC Class. No.: </label>QE155  / .A3 no. 26 
<br/><br/><label>Dewey Class. No.: </label>631.45