BRIEF OHNE UMSCHLAG Krukenberg, Gustav Author: Krukenberg, Gustav Recipient: Haeckel, Ernst Dating: 30.11.1892
BRIEF OHNE UMSCHLAG Krukenberg, Gustav Author: Krukenberg, Gustav Recipient: Haeckel, Ernst Dating: 05.10.1880
BRIEF OHNE UMSCHLAG Krukenberg, Gustav Author: Krukenberg, Gustav Recipient: Haeckel, Ernst Dating: 19.02.1889
BRIEF OHNE UMSCHLAG Krukenberg, Gustav Author: Krukenberg, Gustav Recipient: Haeckel, Ernst Dating: 28.03.1892
BRIEF OHNE UMSCHLAG Krukenberg, Gustav Author: Krukenberg, Gustav Recipient: Haeckel, Ernst Dating: 13.11.1897
BRIEF OHNE UMSCHLAG Krukenberg, Gustav Author: Krukenberg, Gustav Recipient: Haeckel, Ernst Dating: 01.06.1868
BRIEF OHNE UMSCHLAG Krukenberg, Gustav Author: Krukenberg, Gustav Recipient: Haeckel, Ernst Dating: 07.02.1904