BRIEF OHNE UMSCHLAG Bernard, Henry Author: Bernard, Henry Recipient: Haeckel, Ernst Dating: 23.11.1896
BRIEF OHNE UMSCHLAG Bernard, Henry Author: Bernard, Henry Recipient: Haeckel, Ernst Corporation: National History Museum Dating: 08.11.1901
BRIEF OHNE UMSCHLAG Bernard, Henry Author: Bernard, Henry Recipient: Haeckel, Ernst Dating: 20.03.1908