TY  - RPRT
TI  - Map showing distribution pattern of copper from samples of -80 mesh stream sediment, northern Sonora, Mexico
AU  - James G. Frisken
AU  - R. L. Turner
AU  - T. M. Billings
AU  - Guillermo Monroy
AU  - Benjamin Ponce
PY  - 1977
DO  - 10.3133/ofr77338
UR  - https://pubs.usgs.gov/publication/ofr77338
ID  - ofr77338
ER  -