"スマートIC 低コストで地域振興に貢献" [Smart interchanges contribute to regional economy with low costs]. Mainichi Shimbun (in Japanese). 10 December 2015. Retrieved 6 September 2020.
"スマートインターチェンジ開通箇所" [Date of opening and locations of smart interchanges] (PDF) (in Japanese). Ministry of Land, Infrastructure, Transport and Tourism. March 2020. Retrieved 6 September 2020.
pref.ibaraki.jp
"スマートインターチェンジ" [Smart interchange] (in Japanese). Ibaraki Prefectural Government. 21 January 2019. Archived from the original on 12 August 2019. Retrieved 6 September 2020.
web.archive.org
"スマートインターチェンジ" [Smart interchange] (in Japanese). Ibaraki Prefectural Government. 21 January 2019. Archived from the original on 12 August 2019. Retrieved 6 September 2020.