Perspectives on the eastern margin of the Cretaceous Western Interior BasinGeorge W. Shurr, G. A. Ludvigson, R. H. Hammond, Greg A. Ludvigson · First published 1994Open the Tome
Preliminary synthesis of subsurface stratigraphy of the Niobrara formation (Upper Cretaceous) in the northern Great PlainsGeorge W Shurr · First published 1980Open the Tome
