"新型車両 227 系「Urara」運行区間を拡大します" [Service area expansion of the new 227 series "Urara"] (PDF). JR West (in Japanese). Japan. 27 November 2023. Retrieved 22 January 2024.
岡山・福山エリアの主な路線に「路線記号」「ラインカラー」を導入します [Line codes and line colours to be introduced on main lines in Okayama and Fukuyama areas]. News release (in Japanese). Japan: West Japan Railway Company. 17 September 2016. Retrieved 29 March 2016.
