1Alexander von Humboldt to Thomas Jefferson, 20 December 1811 (Jefferson Papers)
Humboldt, Friedrich Wilhelm Heinrich Alexander, Baron von; introduces J. Corrêa da Serra [index...
2José Corrêa da Serra to Thomas Jefferson, 6 March 1812 (Jefferson Papers)
Humboldt, Friedrich Wilhelm Heinrich Alexander, Baron von; introduces J. Corrêa da Serra [index...
3Albert Gallatin to Thomas Jefferson, 10 March 1812 (Jefferson Papers)
Humboldt, Friedrich Wilhelm Heinrich Alexander, Baron von; introduces J. Corrêa da Serra [index...