BRIEF OHNE UMSCHLAG Maurer, Friedrich Author: Maurer, Friedrich Recipient: Haeckel, Ernst Dating: 03.01.1901
BRIEF OHNE UMSCHLAG Maurer, Friedrich Author: Maurer, Friedrich Recipient: Haeckel, Ernst Dating: 28.12.1895
BRIEF OHNE UMSCHLAG Maurer, Friedrich Author: Maurer, Friedrich Recipient: Haeckel, Ernst Dating: 16.02.1894