1Thomas Jefferson to Horatio G. Spafford, 14 May 1809 (Jefferson Papers)
Clavigero, Francesco Saverio; Storia Antica del Messico [index entry]
2Thomas Cooper to Thomas Jefferson, 15 September 1814 (Jefferson Papers)
Clavigero, Francesco Saverio; Storia Antica del Messico [index entry]
3Eusebio Valli to Thomas Jefferson, 5 June 1816 (Jefferson Papers)
Clavigero, Francesco Saverio; Storia Antica del Messico [index entry]