Kaneiji. Columbia University. Accessed June 13, 2008.
nagasaki-u.ac.jp
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Japanese Old Photographs in Bakumatsu/Meiji Period, Shinobazu Pond, accessed on November 16, 2008
uni-tuebingen.de
NengoCalcArchived September 30, 2007, at the Wayback Machine: 明治一年五月十五日; n.b., the old lunar calendar date, used for example by Watanabe, was misidentified as May 15.
web.archive.org
NengoCalcArchived September 30, 2007, at the Wayback Machine: 明治一年五月十五日; n.b., the old lunar calendar date, used for example by Watanabe, was misidentified as May 15.