1Thomas Jefferson to John Wayles Eppes, 5 January 1811 (Jefferson Papers)
2Thomas Jefferson to James Monroe, 17 February 1816 (Jefferson Papers)
3Thomas Jefferson to Peter S. Du Ponceau, 30 December 1817 (Jefferson Papers)
4Peter S. Du Ponceau to Thomas Jefferson, 6 January 1818 (Jefferson Papers)
5Peter S. Du Ponceau to Thomas Jefferson, 22 January 1818 (Jefferson Papers)