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unknown - Public Domain
Mathew Brady (1822-1896) or Levin Handy (1855-1932) - Public Domain
Juliecmi - CC BY-SA 4.0
Webb, William Larkin - Public Domain
Jjkessel - CC BY-SA 3.0
US gov - Public Domain
Bain News Service - Public Domain
César Jiménez - CC BY 2.0
Revista Argentina "Panorama" - Public Domain
William melotti - Public Domain
Amy Richard - CC BY-SA 3.0
Mariusz Kubik, http://www.mariuszkubik.pl - CC BY-SA 3.0
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Holling, C.S.
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Anneke, Mathilde Franziska Giesler, 1817-1884
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Stephens, Lon V., 1858-1923
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unknown - Public Domain
Bloxham, William Dunnington, 1835-1911
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Mathew Brady (1822-1896) or Levin Handy (1855-1932) - Public Domain
Gresham, Walter Quintin, 1832-1895
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Wordsworth, Christopher, 1807-1885
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Juliecmi - CC BY-SA 4.0
Fisher, Mary, 1948-
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Ladd, William, 1778-1841
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Webb, William Larkin - Public Domain
Schiaparelli, G. V. (Giovanni Virginio), 1835-1910
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Lorentz, H.A. (Hendrik Antoon), 1853-1928
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Langbein, August Friedrich Ernst, 1757-1835
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Phillips, Thomas, 1770-1845
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Jjkessel - CC BY-SA 3.0
Kessel, John
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Wegener, Alfred, 1880-1930
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US gov - Public Domain
Montgomery, G. V. (Gillespie V.)
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Saint-Pol-Roux, 1861-1940
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Stoughton, William Lewis, 1827-1888
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Bain News Service - Public Domain
Butt, Archibald Willingham, 1866-1912
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Pompez, Alex, 1890-1974
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Bissell, Clark, 1782-1857
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Bonomi, Joseph, 1796-1878
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César Jiménez - CC BY 2.0
Ruiz de la Prada, Agatha
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Revista Argentina "Panorama" - Public Domain
Parra, Violeta, 1917-1967
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Moodie, William, 1759-1812
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William melotti - Public Domain
Corbett, Ronnie, 1930-
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Eugene IV, Pope, 1383-1447
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Amy Richard - CC BY-SA 3.0
Appel, Libby, 1937-....
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Geer, Ellen
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Mariusz Kubik, http://www.mariuszkubik.pl - CC BY-SA 3.0
Bartoszewski, Władysław
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Enochs, William Henry, 1842-1893