1John Laval to Thomas Jefferson, 25 April 1817 (Jefferson Papers)
The History of Philosophy (W. Enfield) [index entry]
2Thomas Jefferson to Thomas Cooper, 14 August 1820 (Jefferson Papers)
The History of Philosophy (W. Enfield) [index entry]
3Thomas Jefferson to John Adams, 15 August 1820 (Jefferson Papers)
The History of Philosophy (W. Enfield) [index entry]