Soil Classification  : A Comprehensive System 

 - Soil Survey Staff, Soil Conservation Service, United States Department of Agriculture  Washington  1960 
 - 265p.  chart 
 - Approximation  7 .
<br/><br/><label>Nat. Bib. No.: </label>4026 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agriculture
<br/><br/><label>Universal Decimal Class. No.: </label>631.44  / SOI