TY  - RPRT
TI  - Selenium, fluorine, and arsenic in surficial materials of the conterminous United States
AU  - Hansford T. Shacklette
AU  - Josephine G. Boerngen
AU  - John R. Keith
PY  - 1974
DO  - 10.3133/cir692
UR  - https://pubs.usgs.gov/publication/cir692
ID  - cir692
ER  -