TY  - RPRT
TI  - Determination of thorium in the parts per million range in rocks
AU  - H. Levine
AU  - F. S. Grimaldi
PY  - 1958
DO  - 10.1016/0016-7037(58)90096-6
UR  - https://pubs.usgs.gov/publication/70009846
ID  - 70009846
ER  -