BOOKQUE

Experimental Longwall Mining in a Pennsylvania Anthracite Mine (In Two Parts).: Use of yielding steel props
Robert J. Brennan , John W. Buch , Edward R. Navrocky
· 1964
No image available
Anthracite in Pennsylvania
Edward R. Navrocky
· 1930
No image available
Use of Yielding Steel Props
Robert J. Brennan , John W. Buch , Edward R. Navrocky
· 1964
No image available
Experimental Longwall Mining in a Pennsylvania Anthracite Mine: (in Two Parts) : 1.- Use of Yielding Steel Props
Robert J. Brennan , John W. Buch , Edward R. Navrocky
· 1964