TY  - RPRT
TI  - A Rubidium-Strontium study of the Twilight Gneiss, West Needle Mountains, Colorado
AU  - F. Barker
AU  - Z. E. Peterman
AU  - R.A. Hildreth
PY  - 1969
DO  - 10.1007/bf00371424
UR  - https://pubs.usgs.gov/publication/70001725
ID  - 70001725
ER  -