Gill, R.J. <br/><br/>
Stratigraphy and geologic history of the Montana group and equivalent rocks, Montana, Wyoming, and North and South Dakota / 
by J. R. Gill and W. A. Cobban. 
 -- Washington :   United States Government Printing Office,   1973 
 - 37 p. -- 
 (Geological Survey Professional Paper  ; 776).
<br/><br/><label>Subjects--Topical Terms: </label><br/>Dakota del Norte<br/>Dakota del Sur<br/>Estratigrafía<br/>Montana<br/>Wyoming
<br/><br/><label>Universal Decimal Class. No.: </label>551.7(783/787)