Nussbaum, Louis-Frédéric. (2005). "Tenryaku" in Japan Encyclopedia, p. 961, p. 961, at Google Books; n.b., Louis-Frédéric is pseudonym of Louis-Frédéric Nussbaum, see Deutsche Nationalbibliothek Authority File Archived 2012-05-24 at archive.today. https://books.google.com/books?id=p2QnPijAEmEC&pg=PA961
Nussbaum, "Ōwa" at p. 767., p. 767, at Google Books. https://books.google.com/books?id=p2QnPijAEmEC&pg=PA767
Titsingh, Isaac. (1834). Annales ds empereurs du japon, pp. 139–142; Brown, Delmer et al. (1979). Gukanshō, pp. 295–298; Varley, H. Paul. (1980). Jinnō Shōtōki, pp. 183–190. https://books.google.com/books?id=18oNAAAAIAAJ&dq=nipon+o+dai+itsi+ran&pg=PP9
Brown, p. 297.
Titsingh, p. 140. https://books.google.com/books?id=18oNAAAAIAAJ&dq=nipon+o+dai+itsi+ran&pg=PP9
Titsingh, p. 140. https://books.google.com/books?id=18oNAAAAIAAJ&dq=nipon+o+dai+itsi+ran&pg=PP9
Titsingh, p. 141; Brown, p. 297. https://books.google.com/books?id=18oNAAAAIAAJ&dq=nipon+o+dai+itsi+ran&pg=PP9