TY  - RPRT
TI  - Geologic maps and sections of the Helen Beryl, Elkhorn, and Tin Mountain pegmatite mines, South Dakota
AU  - Lincoln R. Page
AU  - Mortimer Hay Staatz
AU  - and others
PY  - 1955
DO  - 10.3133/ofr55128
UR  - https://pubs.usgs.gov/publication/ofr55128
ID  - ofr55128
ER  -