TELEGRAMM Grassi, Giovanni Battista Author: Grassi, Giovanni Battista Recipient: Haeckel, Ernst Dating: 18.05.1911
TELEGRAMM Grassi, Giovanni Battista Author: Grassi, Giovanni Battista Recipient: Haeckel, Ernst Dating: 21.11.1911
BRIEF [O.A.] Grassi, Giovanni Battista Author: Grassi, Giovanni Battista Recipient: Haeckel, Ernst Corporation: Senato del Regno Dating: 16.01.1911