[Besuchskarte an Paul Krüger]
o.O., o.D.[Besuchskarte an Paul Krüger]
Paris, 02.11.1912 [2.11.[19]12][Besuchskarte an Paul Krüger]
o.O., o.D.[Besuchskarte an Paul Krüger]
o.O., o.D.Brief an collègue [Paul Krüger]
Paris, 04.01.1891 [4.1. [18]91]Brief an collègue [Paul Krüger]
Paris, 20.12.1898 [20.12. [18]98]Brief an collègue [Paul Krüger]
[o.O.], 31.12.1898 [Samedi 31.12. [18]98]Brief an collègue [Paul Krüger]
Paris, 12.06.1899 [12.6. [18]99]Brief an collègue [Paul Krüger]
Paris, 05.11.1899 [5.11. [18]99]Brief an collègue [Paul Krüger]
Paris, 16.12.1898 [16.12. [18]98]Brief an collègue [Paul Krüger]
Paris, 11.05.1899 [11.5. [18]99]Brief an collègue [Paul Krüger]
Paris, 15.05.1910 [15.5. [19]10]Brief an Maitre et honoré collègue [Paul Krüger]
Paris, 04.12.1912 [4.12. [19]12]Brief an Professor Dr. Paul Krueger, Bonn, Königstrasse, 21
Paris, 09.12.1898 [9.12. [18]98]Brief an Professor Dr. Paul Krueger, Bonn. König-strasse, 21
Paris, 14.07.1899 [14.7. [18]99]Briefkarte an collègue [Paul Krüger]
Paris, 10.11.1889 [10.XI. [18]89]Briefkarte an collègue [Paul Krüger]
Paris, 20.11.1889 [20.XI. [18]89]Briefkarte an collègue [Paul Krüger]
Paris, 02.12.1889 [2.XII. [18]89]Briefkarte an collègue [Paul Krüger]
Paris, 26.12.1889 [26/12. [18]89]