^"一般国道の路線別、都道府県別道路現況" [Road statistics by General National Highway route and prefecture] (PDF) (in Japanese). Ministry of Land, Infrastructure, Transport and Tourism. Retrieved 19 February 2020.
^一般国道30号 (in Japanese). Ministry of Land, Infrastructure, Transport and Tourism. Shikoku Regional Development Bureau. Archived from the original on 2011-07-21. Retrieved 2010-12-04.