TY  - RPRT
TI  - Data base for a national mineral-resource assessment of undiscovered deposits of gold, silver, copper, lead, and zinc in the conterminous United States
AU  - S. D. Ludington
AU  - D. P. Cox
AU  - R.B. McCammon
PY  - 1996
DO  - 10.3133/ofr9696
UR  - https://pubs.usgs.gov/publication/ofr9696
ID  - ofr9696
ER  -