1Nicolas G. Dufief to Thomas Jefferson, 30 January 1817 (Jefferson Papers)
The History of Philosophy (W. Enfield) [index entry]
2Nicolas G. Dufief to Thomas Jefferson, 7 January 1817 (Jefferson Papers)
The History of Philosophy (W. Enfield) [index entry]
3John Laval to Thomas Jefferson, 25 April 1817 (Jefferson Papers)
The History of Philosophy (W. Enfield) [index entry]
4Nicolas G. Dufief to Thomas Jefferson, 30 January 1817 (Jefferson Papers)
The History of Philosophy (W. Enfield) [index entry]