Schumacherite from North America Plate
USA | |
| Mineralogical Record (1998): 29: 165. |
| Dunning, Gail E., Cooper, Joseph F. Jr. (1998) Namibite: A Summary of World Occurrences. The Mineralogical Record, 29 (3) Tucson. 163-166 |
| Mineralogical Society of America - Handbook of Mineralogy |