亞伯拉罕·林肯的專利(英语:Abraham Lincoln's patent) 林肯的世系图(英语:Lincoln family tree) Robert Todd Lincoln at Harvard College. Abraham Lincoln Online. [17 October 2013]
Historical Guide The Real Lincoln: A Portrait Yeager, Iver (1982), Sesquicentennial Papers, IllinoisCollege. Southern Illinois University Press. ISBN 0809310481
Cannot Escape History": Lincoln and the Last Best Hope of Earth, edited by James M. McPherson. Urbana: University of Illinois Press, 1995. ISBN 978-0-252-02190-9
2013-08-17. 存档副本. [2010-06-23]. (原始内容存档于2010-12-22). University of Nebraska-Lincoln Toolbox. v. 2. June 13, 2007 (PDF). [2014年10月26日]. (原始内容存档 (PDF)于2015年5月1日)