Geological survey research 1972. 

 -- Washington :   United States Government Printing Office,   1972 
 - v. -- 
 (Geological Survey Professional Paper  ; 800).
<br/><br/>Contiene : Vol. I. Chapter A. -- Vol. II. Chapter B. -- Vol. III. Chapter C. -- Vol. IV. Chapter D 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geología
<br/><br/><label>Universal Decimal Class. No.: </label>55