(1995). The cretaceous/tertiary boundary in South-Central North Dakota. North Dakota Geological Survey.
Chicago-Zitierstil (17. Ausg.)The Cretaceous/tertiary Boundary in South-Central North Dakota. Bismarck, ND: North Dakota Geological Survey, 1995.
MLA-Zitierstil (9. Ausg.)The Cretaceous/tertiary Boundary in South-Central North Dakota. North Dakota Geological Survey, 1995.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.