BRIEF MIT UMSCHLAG Haeckel, Ingeborg Author: Haeckel, Ingeborg Recipient: Mentz, Frida Dating: 12.11.1927
BRIEF OHNE UMSCHLAG Haeckel, Ingeborg Author: Haeckel, Ingeborg Recipient: Mentz, Frida Dating: 05.12.1926
BRIEF OHNE UMSCHLAG Haeckel, Walter Author: Haeckel, Walter Recipient: Mentz, Frida Dating: 14.06.1929
BRIEF OHNE UMSCHLAG Haeckel, Walter Author: Haeckel, Walter Recipient: Mentz, Frida Dating: 04.08.1929