TY  - BOOK
AU  - Douglas, William J (Ed.)
TI  - Production systems analysis in underground coal mines
SN  - 0-07-606657-6
U1  - 622.334 21st
PY  - 1980///
CY  - New York
PB  - McGraw-Hill
KW  - Coal mines and mining-Production control; Systems analysis
ER  -