BRIEF OHNE UMSCHLAG Manrique, Antonio Maria Author: Manrique, Antonio Maria Recipient: Haeckel, Ernst Dating: 12.03.1903
BRIEF OHNE UMSCHLAG Manrique, Antonio Maria Author: Manrique, Antonio Maria Recipient: Haeckel, Ernst Dating: 22.07.1903
BRIEF [O.A.] Crespo y Lema, Manuel Author: Crespo y Lema, Manuel Recipient: Haeckel, Ernst Dating: 14.04.1903