Author
Page, William, 1861-1934
25
Doubleday, H. Arthur 1867-1941
5
Salzman, L. F. 1878-
4
Davis, W. W. H. 1820-1910
3
Page, Wm
3
Smith, George, 1804-1882
3
University of London. Institute of Historical Research
3
Chester County Cabinet of Natural Science (West Chester, Pa.)
2
Clemson, Thomas Green, 1807-1888
2
Delaware County Institute of Science (Media, Pa.)
2
Doubleday, H. Arthur
2
Ely, Warren S. 1855-1936
2
Formigli, Donald
2
Jordan, John W. 1840-1921
2
Malden, Henry Elliot
2
Mombert, J. I. 1829-1913
2
Willis Bund, J. W. 1843-1928
2
Adkins, William Ryland Dent, Sir, 1862-1925
1
Bannan, Benjamin, 1807-1875,
1
Barron, Oswald, 1868-1939
1
Bastian, Scott F.
1
Baugh, G. C.
1
Brownbill, J.
1
Chester County Cabinet of Natural Science, West Chester, Pa
1
Cockburn, J. S.
1
Cope, John Hautenville
1
Darlington, William, 1782-1863
1
Delaware County Institute of Science (Delaware County, Pa.)
1
Desor, É. 1811-1882
1
Ditchfield, P. H. 1854-1930
1
Dunning, Robert W. 1938-
1
Dutt, William Alfred, 1870-
1
Elrington, C. R.
1
Essex Institute
1
Farrer, William, 1861-1924
1
Ford, Lisa L.
1
Gaydon, A. T., -1974
1
Geological Society of Pennsylvania
1
Geological Society of Pennsylvania (Philadelphia)
1
Herbert, N. M.
1
Hudson, T. P.
1
Klein, Calvin J.
1
Lewis Publishing Company
1
Meyers, Amy R. W.
1
Miller, Hank,
1
Morton, John, 1671?-1726
1
Moyer, I.S.
1
New Jersey Geological Survey
1
Osborne, Peter
1
Osborne, Peter,
1
more ...