TY  - BOOK
AU  - Penrose,Ray G.
AU  - Holubec,Igor
ED  - United States.
TI  - Laboratory study of self-sealing limestone plugs for mine openings
U1  - 553.516 
PY  - 1973///
CY  - Washington
PB  - U.S. Government Printing Office
KW  - Mine
KW  - Pollution
N1  - EPA-670/2-73-081
ER  -