TY  - RPRT
TI  - Detection of underground voids in Ohio by use of geophysical methods
AU  - Jens Munk
AU  - R. A. Sheets
PY  - 1997
DO  - 10.3133/wri974221
UR  - https://pubs.usgs.gov/publication/wri974221
ID  - wri974221
ER  -