Barker, Fred <br/><br/>
Precambrian geology of the needle mountains, Southwestern Colorado / 
by Fred Barker. 
 -- Washington :   United States Government Printing Office,   1969 
 - 33 p. -- 
 (Geological Survey Professional Paper  ;  644-A).
<br/><br/><label>Subjects--Topical Terms: </label><br/>Colorado<br/>Precámbrico<br/>Rocas ígneas
<br/><br/><label>Universal Decimal Class. No.: </label>552.3(788)"611"