„The Japanese Calendar History”. National Diet Library, Japan. 2002. Архивирано из оригинала 03. 12. 2002. г. Приступљено 19. 3. 2007. National Diet Library, Japan "The Japanese Calendar" - Calendar History 2
See the page on the history of the calendar at the National Diet Library site: [1].
„The Japanese Calendar History”. National Diet Library, Japan. 2002. Архивирано из оригинала 03. 12. 2002. г. Приступљено 19. 3. 2007. National Diet Library, Japan "The Japanese Calendar" - Calendar History 2