TY  - RPRT
TI  - Potassium, uranium, and thorium maps of the conterminous United States
AU  - J. S. Duval
AU  - F. E. Riggle
AU  - J. A. Pitkin
AU  - W. J. Jones
PY  - 1995
DO  - 10.3133/gp1010
UR  - https://pubs.usgs.gov/publication/gp1010
ID  - gp1010
ER  -