Author
United States. Bureau of Mines
3
Baker, Ralph Hillis, 1910-
2
Casey, W. R.
2
Graebner, William
2
Hoyt, J. B.
2
M'Intyre, Arch'd 1772-1858
2
Pennsylvania Commission Appointed to Investigate the Bituminous Coal Mines
2
Pennsylvania. Bureau of Topographic and Geologic Survey
2
Reese, John F.
2
Robertson, Archibald, Philadelphia
2
Sisler, James D.
2
Sisler, James D. 1894-
2
American Liberty League National lawyers committee
1
Ashley, Geo. H. 1866-1951
1
Bedford Iron Company (Bedford & Huntingdon Counties, Pa.)
1
Fritz, Wilbert G.
1
Hotchkiss, Willard E.
1
Longin, Thomas C.
1
National Research Project on Reemployment Opportunities and Recent Changes in Industrial Techniques (U.S.)
1
Pennsylvania
1
Pennsylvania Greater Pennsylvania Council
1
Pennsylvania Inspectors of Mines
1
Pennsylvania. Bituminous Coal Division
1
Philipsburg and Juniata Railroad Company
1
Robinson, H. M. 1845-1907
1
Robinson, Moncure, 1802-1891
1
Skema, Viktoras W.
1
Sponseller, Robert D.
1
United States Bituminous Coal Commission
1
United States. Coal Commission
1
Veenstra, Theodore A.
1
Whitaker, Wm. J. geologist
1
White, John Philip, 1870-
1
Williams, Bruce T.
1