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Gage Skidmore - CC BY-SA 3.0
fabiogoveia - CC BY 2.0
The Huntington - CC BY 2.0
Harris & Ewing - Public Domain
De Lancey W. Gill - Public Domain
Gilbert A. Milne - Public Domain
unknown - Public Domain
U.S. Government - Public Domain
NASA - Public Domain
original uploader - Public Domain
Contact '97 - CC BY 3.0
CBS Radio-logo mark at lower left of uncropped photo - Public Domain
Benjamin West, 1799 - Public Domain
Joeyjojo86 - CC BY-SA 3.0
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Fouts, Roger.
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Silver Horn, 1860-1940
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Séguier, Pierre, 1588-1672
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Gage Skidmore - CC BY-SA 3.0
McFarlane, Todd.
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Merquior, José Guilherme
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fabiogoveia - CC BY 2.0
Negri, Antonio, 1933-....
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The Huntington - CC BY 2.0
Garber, Victor
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Harris & Ewing - Public Domain
Obregón, Álvaro, 1880-1928
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De Lancey W. Gill - Public Domain
McGee, W. J., 1853-1912
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Perkins, Thomas J.
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Gilbert A. Milne - Public Domain
Somers, Harry
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unknown - Public Domain
Khodasevich, V. F. (Vladislav Felit︠s︡ianovich), 1886-1939
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Smith, Sydney, 1771-1845
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U.S. Government - Public Domain
Truax, Robert Collins, 1917-2010
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Maloney, W. (William), 1854-1940
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unknown - Public Domain
Garofalo, Carlo Giorgio, 1886-1962
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Soffici, Ardengo, 1879-1964
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Sitgreaves, Charles, 1803-1878
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Senfl, Ludwig, approximately 1486-1542 or 1543
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NASA - Public Domain
McAuliffe, Christa, 1948-1986
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McAdie, Alexander, 1863-1943
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Brodziński, Kazimierz, 1791-1835
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original uploader - Public Domain
Bennelong, approximately 1764-1813
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Contact '97 - CC BY 3.0
Griffiths, David, 1950-
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CBS Radio-logo mark at lower left of uncropped photo - Public Domain
Lombardo, Victor, 1912-1994
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Oxley, John, 1783-1828
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Hayden, Carl Trumbull, 1877-1972
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Bursum, Holm Olaf, 1867-1953
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Benjamin West, 1799 - Public Domain
Strange, Thomas Andrew Lumisden, 1756-1841
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Joeyjojo86 - CC BY-SA 3.0
Serpico, Frank