TY  - RPRT
TI  - Fission-track ages of zircons from three Tertiary porphyries near Tincup, Colorado
AU  - Charles W. Naeser
AU  - Charles Cunningham
PY  - 1976
DO  - 10.3133/ofr76831
UR  - https://pubs.usgs.gov/publication/ofr76831
ID  - ofr76831
ER  -