TY  - BOOK
AU  - Heok, E
ED  - The Institution of Mining and Metallurgy, Landon
TI  - Undrground Excavations in Rock
U1  - 624.152 
CY  - Landon
N1  - 0; 0; 0; 624_152000000000000_HOE; 0; 0; 0; 624_152000000000000_HOE
ER  -