TY  - RPRT
TI  - Geophysical Investigations 4 and 4a
AU  - W.J. Dempsey
AU  - M. E. Hill
AU  - J. R. Henderson
PY  - 1947
DO  - 10.3133/ofr4723
UR  - https://pubs.usgs.gov/publication/ofr4723
ID  - ofr4723
ER  -