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Kastrel - Public Domain
Who-When-What Company - Public Domain
Internet Archive Book Images - Public Domain
Fotograf Stein - Public Domain
unknown - Public Domain
blahedo - CC BY-SA 2.5
Jonah Most - CC BY-SA 3.0
University of California (1868-1952) -
MEDEF - CC BY-SA 2.0
Photo taken by Vesperholly - CC BY-SA 2.5
George Grantham Bain Collection (Library of Congress) - Public Domain
Neil-logan - CC BY-SA 3.0
anonymous - Public Domain
Vincent Roche - CC BY-SA 2.0
Various - Public Domain
National Science Foundation - Public Domain
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Srinivasa Sastri, V. S. (Valangaiman Sankaranarayana), 1869-1946
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Kastrel - Public Domain
Evans, D. Simon (Daniel Simon)
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Okudzhava, Bulat, 1924-1997
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Ord, William M. (William Miller), 1834-1902
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Winiarski, Bohdan, 1884-
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Who-When-What Company - Public Domain
Smith, Oliver H. (Oliver Hampton), 1794-1859
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Internet Archive Book Images - Public Domain
Mooers, Benjamin, 1758-1838
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Fotograf Stein - Public Domain
Katzer, Fried. X. (Friedrich Xaver), 1844-1903
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unknown - Public Domain
Dale, David, 1739-1806
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La Valette, Antoine-Marie Chamans, comte de, 1769-1830
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Crocker, Walter R. (Walter Russell), 1902-....
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blahedo - CC BY-SA 2.5
Pickens, Andrew, 1739-1817
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Jonah Most - CC BY-SA 3.0
Most, Stephen
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University of California (1868-1952) -
Roemer, Elizabeth, 1929-....
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Coxey, Jacob Sechler, 1854-1951
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MEDEF - CC BY-SA 2.0
Dassier, Jean-Claude
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Bülow, Bernhard Ernst von 1815-1879
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Photo taken by Vesperholly - CC BY-SA 2.5
Hughes, Sarah, 1985-
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George Grantham Bain Collection (Library of Congress) - Public Domain
Fabry, Charles, 1867-1945
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Neil-logan - CC BY-SA 3.0
Murphy, Anthony, 1956-
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anonymous - Public Domain
Shiel, M. P. (Matthew Phipps), 1865-1947
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Vincent Roche - CC BY-SA 2.0
Sisley, Tomer, 1974-....
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Gromyko, Andreĭ Andreevich 1909-1989
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Stewart, Thomas Grainger, 1837-1900
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Zhiyi, 538-597
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unknown - Public Domain
Green, Seth, 1817-1888
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Van Wyck, Robert Anderson, 1849-1918
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Various - Public Domain
Lee, Sidney, Sir, 1859-1926
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National Science Foundation - Public Domain
National Medal of Science.
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unknown - Public Domain
Labastida y Dávalos, Pelagio Antonio de 1815-1891