Hagio Toshiaki 萩尾俊章 (2009). "Yonaguni no kaidā-ji o meguru ichi kōsatsu" 与那国島のカイダー字をめぐる一考察 [A consideration for the "Kaidaa-Ji" (Kaidaa character) in Yonaguni Island]. In Okinawa kenritsu hakubutsukan bijutsukan 沖縄県立博物館・美術館 (Okinawa Prefectural Museum and Art Museum) (ed.). Yonaguni-jima sōgō chōsa hōkokusho 与那国島総合調査報告書 [Survey Reports on Natural History, History and Culture of Yonagunijima Island] (PDF) (in Japanese). pp. 49–64. Retrieved 2020-08-15.
