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(en) Frederic Antes Godcharles, Chronicles of Central Pennsylvania, Lewis historical publishing Company, Incorporated, (lire en ligne), p.330
(en) Kenneth M. Failor et Eleonora Hayden, Medals of the United States Mint, U.S. Government Printing Office, (lire en ligne), p.142
(en) Glover Shipp, In God We Trust . . . Or Do We?: Our Nation Built on a Christian Foundation, Wipf and Stock Publishers, (ISBN978-1-62189-072-0, lire en ligne)
(en) American Philosophical Society, List of Members of the American Philosophical Society, Held at Philadelphia, for Promoting Useful Knowledge ..., The Society, (lire en ligne), p.45, 56
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(en) Charles 0. Paullin, «Abraham Lincoln in Congress, 1847-1849», Journal of the Illinois State Historical Society (1908-1984), vol.14, nos1/2, , p.85–89 (ISSN0019-2287, lire en ligne, consulté le )
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