Contey 2002，第46頁. Contey, F. Zeppelin Mission to East Africa. Aviation History (Weider History Group). 2002, XIII (1). ISSN 1076-8858.
Crowson 2003，第87頁. Crowson, T. A. When Elephants Clash. A Critical Analysis of Major General Paul Emil von Lettow-Vorbeck in the East African Theatre of the Great War. NTIS, Springfield, VA.: Storming Media. 2003. OCLC 634605194.
