Author
Geological Survey of Pennsylvania
3
Pennsylvania. Department of Conservation and Natural Resources
3
Dodge, Clifford H.
2
Roberts, William F.
2
Bedford Iron Company (Bedford & Huntingdon Counties, Pa.)
1
Conner, Eli T.
1
Griffith, William, 1855-
1
Lea, Isaac, 1792-1886
1
Pennsylvania
1
Pequa Railroad and Improvement Company
1
Shaulis, James R.
1
Slocum Coal, Iron and City Improvement Company
1
Stafford Meadow Coal, Iron and City Improvement Company
1
Whitaker, Wm. J. geologist
1
X.
1