Author
Pennsylvania. Bureau of Topographic and Geologic Survey
36
Geological Survey (U.S.)
13
Pennsylvania Geological Survey
13
Lewis, Samuel, -1865
9
Stone, Ralph W. 1876-1964
9
Fettke, Charles R. 1888-1959
8
Willard, Bradford, 1894-
7
Ashley, Geo. H. 1866-1951
6
Melish, John, 1771-1822
6
Minert, Roger P. 1952-
6
Britton, John
5
Imlay, Gilbert, 1754?-1828?
5
Rupp, I. Daniel 1803-1878
5
Wagner, Walter Richard, 1928-1974
5
Charles D. Hevenor Company
4
Elmes, James, 1782-1862
4
Foster, Margaret Dorothy, 1895-
4
Goodenow
4
Hutchins, Thomas, 1730-1789
4
Kuchinski, John G.
4
Miller, Benjamin L. 1874-1944
4
Pennsylvania. Department of Conservation and Natural Resources
4
Sisler, James D. 1894-
4
United States. Army. Corps of Topographical Engineers
4
Willard, Bradford
4
Yonge, Samuel H.
4
Barnes, John Henry, 1946-
3
Bartholomew, J. G. 1860-1920
3
Behre, Chas. H.
3
Brayley
3
Cozart, Cheryl L.
3
Faill, Rodger T.
3
Filson, John, approximately 1747-1788
3
Gardner, David E.
3
Geological Survey of Pennsylvania
3
Geyer, Alan R.
3
Harland, Derek
3
Harper, John A.
3
Kennedy, Patrick
3
Lewis, Samuel
3
Lohman, S. W. 1907-1992
3
Penn Bureau of Topographic and Geologic Survey
3
Shepherd, Thomas H.
3
Smith, Frank
3
Swartz, F. M.
3
Swett, Samuel, 1782-1866
3
United States. Bureau of Mines
3
Adamson, John Howard
2
American Imprint Collection (Library of Congress)
2
Asher & Adams
2
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