BRIEF [O.A.] Schultze, Leonhard Author: Schultze, Leonhard Recipient: Haeckel, Ernst Dating: 13.10.1915
BRIEF [O.A.] Schultze, Leonhard Author: Schultze, Leonhard Recipient: Haeckel, Ernst Dating: 22.01.1915
BRIEF OHNE UMSCHLAG Schultze, Leonhard Author: Schultze, Leonhard Recipient: Haeckel, Ernst Dating: 22.01.1915