TY  - RPRT
TI  - Summary of mineral resources in four selected areas of Colombia
AU  - Charles MaFarland Tschanz
AU  - R.B. Hall
AU  - T. Feininger
AU  - D.E. Ward
AU  - R. Goldsmith
AU  - D.H. MacLaughlin
AU  - E. Maughan
PY  - 1968
DO  - 10.3133/ofr68279
UR  - https://pubs.usgs.gov/publication/ofr68279
ID  - ofr68279
ER  -