Brown, Delmer M. and Ichirō Ishida, eds. (1979). Gukanshō: The Future and the Past. Berkeley: University of California Press. ISBN 978-0-520-03460-0; OCLC 251325323
Titsingh, Isaac. (1834). Nihon Ōdai Ichiran; ou, Annales des empereurs du Japon. Paris: Royal Asiatic Society, Oriental Translation Fund of Great Britain and Ireland. OCLC 5850691
Titsingh, p. 122; Varley, p. 44; a distinct act of senso is unrecognized prior to Emperor Tenji; and all sovereigns except Jitō, Yōzei, Go-Toba, and Fushimihave senso and sokui in the same year until the reign of Emperor Go-Murakami.