西鉄9000形が営業運転を開始 [Nishitetsu 9000 series enters revenue service]. Japan Railfan Magazine Online (in Japanese). Japan: Koyusha Co., Ltd. 21 March 2017. Archived from the original on 21 March 2017. Retrieved 21 March 2017.
sankei.com
西鉄、新型車両「9000形」導入 来年3月、軽量化や省エネ図る [Nishitetsu to introduce new 9000 series next March with light weight and energy savings]. Sankei News (in Japanese). Japan: Sankei Shimbun & Sankei Digital. 5 February 2016. Archived from the original on 5 February 2016. Retrieved 21 March 2017.
tetsudo-shimbun.com
西日本鉄道、天神大牟田線に新型車両「9000形」デビューへ [Nishi-Nippon Railroad to introduce new 9000 series on Tenjin Ōmuta Line] (in Japanese). Japan: Tetsudo Shimbun. 4 February 2016. Archived from the original on 10 September 2016. Retrieved 21 March 2017.
web.archive.org
西日本鉄道、天神大牟田線に新型車両「9000形」デビューへ [Nishi-Nippon Railroad to introduce new 9000 series on Tenjin Ōmuta Line] (in Japanese). Japan: Tetsudo Shimbun. 4 February 2016. Archived from the original on 10 September 2016. Retrieved 21 March 2017.
西鉄、新型車両「9000形」導入 来年3月、軽量化や省エネ図る [Nishitetsu to introduce new 9000 series next March with light weight and energy savings]. Sankei News (in Japanese). Japan: Sankei Shimbun & Sankei Digital. 5 February 2016. Archived from the original on 5 February 2016. Retrieved 21 March 2017.
西鉄9000形が営業運転を開始 [Nishitetsu 9000 series enters revenue service]. Japan Railfan Magazine Online (in Japanese). Japan: Koyusha Co., Ltd. 21 March 2017. Archived from the original on 21 March 2017. Retrieved 21 March 2017.