Ross, Clarence Samuel   1880-1975 <br/><br/>
Ash-flow tuffs : their origin geologic relations and identification / 
by Clarence S. Ross and Robert L. Smith. 
 -- Washington :   United States Government Printing Office,   1961 
 - 81 p. -- 
 (Geological Survey Professional Paper  ; 366).
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geología
<br/><br/><label>Universal Decimal Class. No.: </label>55