Bevan Brittan LLC (26 March 2014). The Northern Interim Franchise Agreement(PDF). London: Department for Transport. M-10204941-1. Archived(PDF) from the original on 4 January 2015. Retrieved 22 April 2015.
"Flood-damaged DMU returns to service". Railway Gazette International. DVV Media International. 19 October 2016. Archived from the original on 26 December 2017. Retrieved 28 November 2018.
"Class 156". The Railway Centre. Archived from the original on 9 March 2005.
Bevan Brittan LLC (26 March 2014). The Northern Interim Franchise Agreement(PDF). London: Department for Transport. M-10204941-1. Archived(PDF) from the original on 4 January 2015. Retrieved 22 April 2015.
"Flood-damaged DMU returns to service". Railway Gazette International. DVV Media International. 19 October 2016. Archived from the original on 26 December 2017. Retrieved 28 November 2018.