1To Benjamin Franklin from Heinrich Ehrenfried Luther, May 1765 (Franklin Papers)
MS : Massachusetts Archives, Office of the Secretary of State Puisque M. Gmelin, Capt. au Service...
2To Benjamin Franklin from Heinrich Ehrenfried Luther, 16 March 1767 (Franklin Papers)
LS : American Philosophical Society L’honneur de l’agréable vôtre du 9. 7bre de l’année derniere...