TY  - RPRT
TI  - Natural gamma aeroradioactivity of the District of Columbia and parts of Maryland, Virginia, and West Virginia
AU  - S.K. Neuschel
PY  - 1965
DO  - 10.3133/gp475
UR  - https://pubs.usgs.gov/publication/gp475
ID  - gp475
ER  -