Author
Geological Survey (U.S.)
57
Geological Survey of Pennsylvania
7
United States. National Aeronautics and Space Administration
7
United States. Army. Corps of Engineers
6
Weary, David J.
6
New York State Geological Survey
5
United States. War Department
5
Decade of North American Geology Project
4
Geological Survey of Canada
4
Planetary Geology and Geophysics Program (U.S.)
4
Ruedemann, Rudolf, 1864-1956
4
Lettis, William R.
3
Noller, Jay S.
3
Orndorff, Randall C.
3
Pennsylvania. Department of Conservation and Natural Resources
3
Ryan, Darlene A.
3
Sowers, Janet M.
3
United States. Army. Office of the Chief of Engineers
3
United States. National Park Service
3
Afghanistan. Department of Geological Survey
2
Afghanistan. Idārah-i ʻUmūmī-i Jiyūdīzī va Kārtūgrāfī
2
Alaska. Division of Oil and Gas
2
Alling, Harold L. (Harold Lattimore), 1888-1960
2
Berkey, Charles Peter, 1867-1955
2
Bohannon, Robert G.
2
Dodge, Clifford H.
2
Du Bray, E. A.
2
Eckstrand, O. R. (Olof Roger)
2
Featherstonhaugh, George William, 1780-1866
2
Geological Society of America
2
Goldring, Winifred, 1888-1971
2
Isachsen, Yngvar W., 1920-
2
Kellogg, Karl S.
2
Kemp, James Furman, 1859-1926
2
Landing, Ed
2
Lucas, Spencer G.
2
Mull, Charles G.
2
New Mexico Museum of Natural History and Science
2
New York State Museum
2
North Dakota Geological Survey
2
Pennsylvania. Board of Commissioners for the Second Geological Survey
2
Ray, Richard G. (Richard Godfrey), 1920-
2
Scott, Robert B.
2
Sinclair, W. D.
2
Southworth, Scott, 1957-
2
Swadley, W. C.
2
Thorpe, R. I.
2
United States. Agency for International Development
2
United States. Office of Space Science and Applications
2
University of the State of New York
2
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