BRIEF [O.A.] Hill, Isabella W... Author: Hill, Isabella W... Recipient: Haeckel, Ernst Dating: 07.06.1910
BRIEF [O.A.] Hill, Isabella W... Author: Hill, Isabella W... Recipient: Haeckel, Ernst Dating: 18.05.1911
POSTKARTE Hill, Isabella W... Author: Hill, Isabella W... Recipient: Haeckel, Ernst Dating: 26.05.1911