Brief [an Otto Toeplitz]
Gießen, 04.07.1922 [4/7/ [19]22]Brief an [Ernst] Hellinger
Bonn, 24.11.1931 [24. November 1931]Brief an [Helmut] Ulm
Köln, 25.01.1938 [25.1.[19]38]Brief an [Helmut] Ulm
Bonn, 26.03.1937 [26.3.[19]37]Brief an [Helmut] Ulm
Bonn, 03.08.1936 [3.8. [19]36]Brief an [Helmut] Ulm
Bonn, 01.05.1935 [1. Mai 1935]Brief an [Helmut] Ulm
Bonn, 27.04.1935 [27. April 1935]Brief an [Helmut] Ulm
Bonn, 19.11.1933 [19. November 1933]Brief an [Helmut] Ulm
Bonn, 27.05.1933 [27. Mai 1933]Brief an [Helmut] Ulm
Bonn, 27.04.1933 [27. April 1933]Brief an [Helmut] Ulm
Bonn, 16.03.1932 [16/3.[19]32]Brief an [Helmut] Ulm
Bonn, 02.03.1932 [2/3.[19]32]Brief an [Helmut] Ulm
Bonn, 12.11.1931 [12.11.[19]31]Brief an [Helmut] Ulm
Bonn, 07.10.1931 [7.10.[19]31]Brief an [Helmut] Ulm
Bonn, 06.07.1931 [6.7. [19]31]Brief an [Helmut] Ulm
Bonn, 20.04.1931 [20. April 1931]Brief an [Helmut] Ulm
Bonn, 22.02.1931 [22.II.1931]Brief an [Helmut] Ulm
Bonn, 30.01.1931 [30.1. [19]31]Brief an [Helmut] Ulm
Bonn, 29.11.1930 [29.11. [19]30]