BRIEF OHNE UMSCHLAG Watts, Charles Albert Author: Watts, Charles Albert Recipient: Haeckel, Ernst Dating: 03.07.1903
BRIEF OHNE UMSCHLAG McCabe, Joseph Author: McCabe, Joseph Recipient: Haeckel, Ernst Dating: 21.04.1903
BRIEF OHNE UMSCHLAG McCabe, Joseph Author: McCabe, Joseph Recipient: Haeckel, Ernst Dating: 22.09.1903
BRIEF OHNE UMSCHLAG Watts, Charles Albert Author: Watts, Charles Albert Recipient: Haeckel, Ernst Corporation: The Rationalist Press Association Dating: 14.02.1903