TY  - RPRT
TI  - Resource targets for advanced underground coal extraction systems
AU  - Hoag, J. H.
AU  - Whipple, D. W.
AU  - Habib-Agahi, H.
AU  - Lavin, M. L.
PY  - 1982
UR  - https://ntrs.nasa.gov/citations/19830002233
ID  - 19830002233
ER  -