1Thomas Jefferson to Peter Wilson, 20 January 1816 (Jefferson Papers)
Pallas, Peter Simon; editsLinguarum Totius Orbis Vocabularia comparativa [index entry]
2Peter S. Du Ponceau to Thomas Jefferson, 11 December 1817 (Jefferson Papers)
Pallas, Peter Simon; editsLinguarum Totius Orbis Vocabularia comparativa [index entry]
3Thomas Jefferson to Peter S. Du Ponceau, 30 December 1817 (Jefferson Papers)
Pallas, Peter Simon; editsLinguarum Totius Orbis Vocabularia comparativa [index entry]