1John Adams to Thomas Jefferson, February–3 March 1814 (Jefferson Papers)
Hicks, Robert D., trans.; Lives of Eminent Philosophers (Diogenes Laertius) [index entry]
2John Adams to Thomas Jefferson, 3 December 1813 (Jefferson Papers)
Hicks, Robert D., trans.; Lives of Eminent Philosophers (Diogenes Laertius) [index entry]