BRIEF OHNE UMSCHLAG Haeckel, Walther Author: Haeckel, Walther Recipient: Haeckel, Julius Dating: 22.02.1903
BRIEF OHNE UMSCHLAG Haeckel, Walther Author: Haeckel, Walther Recipient: Haeckel, Julius Corporation: Zoologisches Institut der Universität Jena Dating: 18.02.1903
BRIEF OHNE UMSCHLAG Haeckel, Walther Author: Haeckel, Walther Recipient: Haeckel, Julius Dating: 20.02.1903