NOTES:

• "Sprechmaschinen-Aufnahmen unter den Pyramiden" in: Phonographische Zeitschrift 6. Jahrg., No. 10, p. 221 (8 March 1905)

• "In 9 Monaten Europa erobert in haben die Beka-Records" in: Phonographische Zeitschrift 6. Jahrg., No. 11, p. 237 (15 March 1905)

• "In 9 Monaten Europa erobert in haben die Beka-Records" in: Phonographische Zeitschrift 6. Jahrg., No. 12, p. 271 (22 March 1905)

• "Eisenbahn-Unfall der Beka-Expedition." in: Phonographische Zeitschrift 6. Jahrg., No. 42, p. 925 (18 Oct 1905)

• "Unsere Reise um die Erde": a series of articles by Heinrich Bumb in the Phonographische Zeitschrift 7. Jahrg. No. 27, pp. 561-563; No. 28, pp. 582-584; No. 29, pp. 602-604; No. 30, pp. 622-623; No. 31, pp. 643-645; No. 32, pp. 662-664; No. 33, pp. 692; No. 34, pp. 718-720; No. 35, pp. 759-760; No. 36, pp. 788-789; No. 37, pp. 808-809).

• "The Great Beka Expedition, 1905-6" translated and adapted by John Want in The Talking Machine Review No. 41 of Aug 1976, pp. 729-733

• Obituary in: Phonographische Zeitschrift 13. Jahrg. No. 37, p. 862 (11 Sep 1912)

• "Favorite: the story of an independent German record company (1904-1914)" by Hugo Strötbaum (in: The Lindström Project. Contributions to the history of the record industry / Beiträge zur Geschichte der Schallplattenindustrie. Vol. 2 (editors: Pekka Gronow & Christiane Hofer). Gesellschaft für Historische Tonträger, Wien 2010. ISBN 978-3-9500502-1-9