BRIEF [O.A.] Schulze, Franz Eilhard Author: Schulze, Franz Eilhard Recipient: Haeckel, Ernst Dating: 17.05.1911
BRIEF OHNE UMSCHLAG Singer, Isidore Author: Singer, Isidore Recipient: Haeckel, Ernst Corporation: The German Classics of the XIXth and XXth Centuries Dating: 14.08.1911