Geological Survey research 1963 / 
director Thomas B. Nolan. 
 -- Washington :   United States Government Printing Office,   1963 
 - 300 p. -- 
 (Geological Survey Professional Paper  ; 475).
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geología
<br/><br/><label>Universal Decimal Class. No.: </label>55