1Thomas Jefferson to Pierre Samuel Du Pont de Nemours, André Thoüin, and Bartelémy de Faujas-Saint Fond, 16 May 1809 (Jefferson Papers)
Oeuvres (A. R. J. Turgot) [index entry]
2Thomas Jefferson to Pierre Samuel Du Pont de Nemours, 29 November-14 December 1813 (Jefferson Papers)
Oeuvres (A. R. J. Turgot) [index entry]