[Individuals]: Schwerz, E. [Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.22 - Kamerun #1906
[Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.22 - Kamerun #1906
[Individuals]: Dorsch, H. [Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.22 - Kamerun #1906
[Individuals]: Köster, H. [Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.23 - Kamerun #1907
[Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.23 - Kamerun #1907
[Individuals]: Otto Solleder [Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.24 - Kamerun #1907
[Individuals]: Francis Chapuis [Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.24 - Kamerun #1907
[Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.24 - Kamerun #1907
[Individuals]: Kohl [Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.25 - Kamerun #Quartal- und Jahresberichte#1893
[Individuals]: Köster, H. [Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.27 - Kamerun #1908
[Archives catalogue]: Maps and plans: E - Cameroon maps and plans: E-02: E-02.27 - Kamerun #1908