1Thomas Jefferson to Robert Walsh, 19 February 1818 (Jefferson Papers)
Correspondance littéraire, philosophique et critique (F. M. Grimm) [index entry]
2Thomas Jefferson to Robert Walsh, 20 July 1818 (Jefferson Papers)
Correspondance littéraire, philosophique et critique (F. M. Grimm) [index entry]
3Thomas Jefferson to Robert Walsh, 11 April 1819 (Jefferson Papers)
Correspondance littéraire, philosophique et critique (F. M. Grimm) [index entry]