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David Shankbone - CC BY-SA 3.0
Public Domain
unknown - Public Domain
U.S. Army Signal Corps - Public Domain
יעקב - CC BY-SA 3.0
Fotograf im Auftrag der :de:United States Information Agency - Public Domain
Harris & Ewing - Public Domain
Stellar Publishing / unidentified staff artist(s) - Public Domain
United States Congress - Public Domain
Carlo Dolci - Public Domain
U.S. Government Printing Office. - Public Domain
Nadya Peek - CC BY-SA 2.5
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Sidney, Philip, 1554-1586
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Severus, Lucius Septimius, Emperor of Rome, 146-211
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David Shankbone - CC BY-SA 3.0
Lake, Ricki
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Britton, Paméla 1923-1974
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Public Domain
Glass, Carter, 1858-1946
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unknown - Public Domain
Weissert, Augustus Gordon, 1843-1923
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Euler, Leonhard
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Poulson, Zachariah, 1761-1844
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U.S. Army Signal Corps - Public Domain
Rhodes, Charles Dudley, 1865-1948
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Fairchild, Herman L. (Herman Le Roy), 1850-1943
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יעקב - CC BY-SA 3.0
Orlev, Uri, 1931-....
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Bucci, Anselmo, 1887-1955
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Scott, Hugh Lenox, 1853-1934
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Fotograf im Auftrag der :de:United States Information Agency - Public Domain
Torberg, Friedrich, 1908-1979
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Fajans, Kasimir, 1887-1975
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Harris & Ewing - Public Domain
Alger, Philip R. (Philip Rounseville), 1859-1912
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Stellar Publishing / unidentified staff artist(s) - Public Domain
Bell, Eric Temple, 1883-1960
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unknown - Public Domain
Ringling, William Otto, 1858-1911
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Clarke, Samuel, 1599-1682
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unknown - Public Domain
Williams, Daniel Hale, 1856-1931
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Capponi, Raffaelo de 1466?-1524
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United States Congress - Public Domain
Zorinsky, Edward, 1928-1987
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Moore, Lindley M. (Lindley Murray), 1788-1871
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Carlo Dolci - Public Domain
Dolci, Carlo, 1616-1686
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U.S. Government Printing Office. - Public Domain
Smith, Lawrence Henry, 1892-1958
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Mascheroni, Edoardo
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Ochiltree, Thomas P. (Thomas Peck), 1837-1902
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Fell, Jesse W., 1808-1887
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unknown - Public Domain
Laidlie, Archibald, 1727-1779
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Nadya Peek - CC BY-SA 2.5
Bakker, Gijs, 1942-....