Dudenredaktion; Kleiner, Stefan; Knöbl, Ralf (2015) [First published 1962]. Das Aussprachewörterbuch [The Pronunciation Dictionary] (in German) (7th ed.). Berlin: Dudenverlag. pp. 512, 567. ISBN978-3-411-04067-4.
Krech, Eva-Maria; Stock, Eberhard; Hirschfeld, Ursula; Anders, Lutz Christian (2009). Deutsches Aussprachewörterbuch [German Pronunciation Dictionary] (in German). Berlin: Walter de Gruyter. pp. 655, 712. ISBN978-3-11-018202-6.
"VfLer für U15-Lehrgänge nominiert" (in German). VfL Bochum. 29 September 2010. Archived from the original on 26 December 2017. Retrieved 26 December 2017. "Talente unterwegs" (in German). VfL Bochum. 15 September 2011. Archived from the original on 26 December 2017. Retrieved 26 December 2017.
"VfLer für U15-Lehrgänge nominiert" (in German). VfL Bochum. 29 September 2010. Archived from the original on 26 December 2017. Retrieved 26 December 2017. "Talente unterwegs" (in German). VfL Bochum. 15 September 2011. Archived from the original on 26 December 2017. Retrieved 26 December 2017.