11Thomas Jefferson to Pierre Samuel Du Pont de Nemours, 3 August 1816 (Jefferson Papers)
Ritchie, Thomas; and works of Destutt de Tracy [index entry]
12Thomas Jefferson to Destutt de Tracy, 24 November 1818 (Jefferson Papers)
Ritchie, Thomas; and works of Destutt de Tracy [index entry]
13Joseph Milligan to Thomas Jefferson, 25 December 1818 (Jefferson Papers)
Ritchie, Thomas; and works of Destutt de Tracy [index entry]