"Züge zwischen Düsseldorf-Köln rollen wieder" [Trains between Dusseldorf and Cologne running again]. Kölner Stadt-Anzeiger (in German). 24 September 2023. Retrieved 27 September 2023.
"Verkehrsentwicklung im SPNV NRW bis 2030" [Rail travel traffic development in NRW until 2030] (PDF). Landtag Nordrhein-Westfalen (in German). 6 February 2015. Archived from the original(PDF) on 12 August 2018. Retrieved 12 July 2023.
"Probleme zum Start des RRX erwartet" [Problems during the start of the RRX expected]. Rheinische Post (in German). 14 April 2019. Retrieved 12 July 2023.
"Düsseldorf: 25 Jahre bis zum RRX" [Düsseldorf: 25 years until the RRX operates]. Rheinische Post (in German). 31 October 2018. Retrieved 12 July 2023.
"Verkehrsentwicklung im SPNV NRW bis 2030" [Rail travel traffic development in NRW until 2030] (PDF). Landtag Nordrhein-Westfalen (in German). 6 February 2015. Archived from the original(PDF) on 12 August 2018. Retrieved 12 July 2023.