|
USA | |
| Roberts, Willard Lincoln, Rapp, George Jr. (1965) Mineralogy of the Black Hills. Bulletin 18. South Dakota School of Mines and Technology |
| Smith, Arthur E., Fritzsch, Eric (2000) SOUTH DAKOTA. Rocks & Minerals, 75 (3) 156-169 doi:10.1080/00357520009605635 |
| www.dakotamatrix.com/Southdakota/VeinNtoQ.htm. |
| Roberts, Willard Lincoln, Rapp, George Jr. (1965) Mineralogy of the Black Hills. Bulletin 18. South Dakota School of Mines and Technology |
| Roberts, Willard Lincoln, Rapp, George Jr. (1965) Mineralogy of the Black Hills. Bulletin 18. South Dakota School of Mines and Technology |
| [var. Strüverite] Rocks & Minerals: 57: 160 &/or 60: 110 & 112. |
| [var. Strüverite] Černý, P., Roberts, W. L., Ercit, T. S., Chapman, R. (1985) Wodginite and associated oxide minerals from the Peerless pegmatite, Pennington County, South Dakota. American Mineralogist, 70 (9-10) 1044-1049 USGS Prof Paper 297A |
| E.L. Clopton collection |
Upper Spring Creek quarry, Pennington County, South Dakota, USA