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USA | |
| Murphy, Edward C. (1995), North Dakota Clays, A Historical Review of Clay Utilization in North Dakota, North Dakota Geological Survey, Miscellaneous Series No. 79: 2. |
| Geology of Morton County, North Dakota. Bulletin (North Dakota Geological Survey) , 72 |
| Murphy, Edward C. (1995), North Dakota Clays, A Historical Review of Clay Utilization in North Dakota, North Dakota Geological Survey, Miscellaneous Series No. 79: 6-7. |
| www.dmr.nd.gov (2009) https://www.dmr.nd.gov/ndgs/Mineral/nd_claynew.asp |
| Murphy, E.C. (1995) North Dakota Clays, A Historical Review of Clay Utilization in North Dakota. North Dakota Geological Survey, Miscellaneous Series No. 79, 18 pages at p. 3-4. |