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unknown photographer - Public Domain
DEDB - Public Domain
Smmcp - CC BY-SA 3.0
Lubos Motl, Lumidek - CC BY 3.0
Aimé Dupont - Public Domain
Everts & Fariss (Philadelphia), publishers. - Public Domain
William Lee Hankey - Public Domain
William Wells Brown. - Public Domain
unknown - Public Domain
Lyman Horace Weeks, John Hampden Dougherty - Public Domain
Public Domain
Erling Mandelmann - CC BY-SA 3.0
Julienmorvan - Public Domain
Brianmcmillen - CC BY-SA 4.0
Thierry Bellange - Public Domain
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Morrow, Buddy
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Belsham, Thomas, 1750-1829
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Bradley, Milton, 1836-1911
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unknown photographer - Public Domain
Poland, Joseph F.
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DEDB - Public Domain
Otter, Anne Sofie von
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Smmcp - CC BY-SA 3.0
Colgate, William, 1783-1857
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McClory, Robert, 1908-1988
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Lubos Motl, Lumidek - CC BY 3.0
Jaffe, Arthur, 1937-....
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Aimé Dupont - Public Domain
Rehan, Ada, 1857-1916
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Everts & Fariss (Philadelphia), publishers. - Public Domain
Prentiss, John Holmes, 1784-1861
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William Lee Hankey - Public Domain
Lee-Hankey, William, 1869-1952
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Chubb, Thomas, 1679-1747
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William Wells Brown. - Public Domain
Brown, William Wells, 1814?-1884
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Miki, Takeo, 1907-1988
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Bede, the Venerable, Saint, 673-735
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unknown - Public Domain
Wuttke, Heinrich, 1818-1876
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Lyman Horace Weeks, John Hampden Dougherty - Public Domain
Parker, Amasa J. (Amasa Junius), 1807-1890
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Public Domain
Huntington, Jabez Williams, 1788-1847
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Erling Mandelmann - CC BY-SA 3.0
Besson, Benno, 1922-2006
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unknown - Public Domain
Pearson, Edmund Lester, 1880-1937
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Julienmorvan - Public Domain
Benguigui, Jean, 1944-....
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Curtis, Charles, 1860-1936
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Tournefort, Joseph Pitton de 1656-1708
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Caccini, Francesca, 1587-approximately 1640
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unknown - Public Domain
Droysen, Johann Gustav, 1808-1884
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unknown - Public Domain
Lyman, Chester Smith, 1814-1890
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Reichenbach, Karl, Freiherr von, 1788-1869
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Rothier, Léon 1874-1951
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Brianmcmillen - CC BY-SA 4.0
Land, Harold
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Thierry Bellange - Public Domain
Montpensier, Louis de Bourbon, duc de, 1513-1582