TY  - RPRT
TI  - Microwave detection of lost wells and unknown water-filled voids in coal mines 
AU  - Belsher, D R
AU  - McKaughlin, R H
AU  - Repair, A G
AU  - Bussey, H E
PY  - 1984
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS IR 84-3017
DO  - 10.6028/NBS.IR.84-3017
ER  -