Pettyjohn, W. A. (1967). Geological Survey Geohydrology of the Souris River valley in the vicinity of Monot, North Dakota. Washington: United States Government Printing Office.
Chicago-referens (17:e uppl.)Pettyjohn, Wayne A. Geological Survey Geohydrology of the Souris River Valley in the Vicinity of Monot, North Dakota. Washington: United States Government Printing Office, 1967.
MLA-referens (9:e uppl.)Pettyjohn, Wayne A. Geological Survey Geohydrology of the Souris River Valley in the Vicinity of Monot, North Dakota. Washington: United States Government Printing Office, 1967.
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