org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse English German HeinrichGustavMagnus, Lithographie von Rudolf Hoffmann, 1856
1780-1856 + Johann Christian Poggendorf 1796-1877 + GustavMagnus 1802-1870 Heinrich Dove 1803-1879 + Carl Gustav Jakob Jacobi 1804-1851 + Hermann von Helmholtz