Gill, R.J.
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).
Dakota del Norte
Dakota del Sur
Estratigrafía
Montana
Wyoming
551.7(783/787)
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).
Dakota del Norte
Dakota del Sur
Estratigrafía
Montana
Wyoming
551.7(783/787)