1. Tamamura Takeji . “Takuan Sōhō: shie jiken ni taisuru ichi kenkai”. In Tamamura Takeji, Nihon Zenshūshi ronshū. Vol. 1. Kyoto: Shibunkaku, 1976.
2. kassen nikki surname , quoted in Kagoshima-ken, vol. 46 of Kadokawa Nihon chimei daijiten (Tokyo: Kadokawa shoten, 1983).
3. Wajima shishi hensan semmon iinkai , ed. Wajima shishi. Vol. 1. Wajima: Wajima shiyakusho, 1976.
4. Ōkuwa Hitoshi . Jidan no shisō. Vol. 177 of Kyōikusha rekishi shinsho: Nihonshi. Tokyo: Kyōikusha, 1979.
5. Epistolae Xavier to the Jesuits of Europe, dated Couchim, January 29, 1552, vol. 2, no. 96.