"宇都宮線・日光線に新型車両を投入します" [New train sets for the Utsunomiya and Nikko Lines] (PDF). 17 June 2021. Retrieved 17 June 2021.
railf.jp
日光線用107系が営業運転を終了 [Nikko Line 107 series withdrawn from service]. Japan Railfan Magazine Online (in Japanese). Japan: Koyusha Co., Ltd. 16 March 2013. Retrieved 1 April 2013.