1Thomas Jefferson to Thomas Ritchie, 27 September 1814 (Jefferson Papers)
A Treatise on Political Economy (Destutt de Tracy) [index entry]
2Thomas Jefferson to Thomas Ritchie, 8 March 1816 (Jefferson Papers)
A Treatise on Political Economy (Destutt de Tracy) [index entry]
3Thomas Jefferson to Thomas Ritchie, 6 April 1816 (Jefferson Papers)
A Treatise on Political Economy (Destutt de Tracy) [index entry]