Ross, Reuben James  1918-2005 <br/><br/>
Distribution of the middle ordovician Copenhagen formation and its Trilobites in Nevada / 
by Reuben James Ross and Frederick C. Shaw. 
 -- Washington :   United States Government Printing Office,   1972 
 - 33 p., [8] h. de lam. -- 
 (Geological Survey Professional Paper  ; 749).
<br/><br/><label>Subjects--Topical Terms: </label><br/>Artrópodos fósiles<br/>Nevada<br/>Trilobites
<br/><br/><label>Universal Decimal Class. No.: </label>565.2(793)