BRIEF MIT UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Diederichs, Eugen Dating: 11.04.1905
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Diederichs, Eugen Corporation: Zoologisches Institut der Universität Jena Dating: 15.05.1905
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Diederichs, Eugen Corporation: Zoologisches Institut der Universität Jena Dating: 15.03.1906
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Diederichs, Eugen Dating: 27.03.1905
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Diederichs, Eugen Dating: 28.02.1909
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Diederichs, Eugen Dating: 22.11.1909
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Diederichs, Eugen Dating: 14.07.1914