Schmidt, Tom (November 21, 2010), Hippolytus and the Original Date of Christmas, chronicon.net, archived from the original on March 3, 2013, retrieved December 29, 2018. Schmidt is translator of Hippolytus of Rome: Commentary on Daniel and 'Chronicon'.
jstor.org
Nordenfalk, "Der Kalendar vom Jahre 354 und die lateinische Buchmalerei des IV. Jahrhunderts" (Göteborg) 1936, noted in Schapiro 1940:270, reprinted in Schapiro, Selected Papers: volume 3, Late Antique, Early Christian and Mediaeval Art, 1980, Chatto & Windus, London, ISBN0-7011-2514-4On line at JSTOR
The writer most likely based his numbers from Cassius Dio(63), who also gave Galba a larger reign ("nine months and thirteen days").
web.archive.org
Schmidt, Tom (November 21, 2010), Hippolytus and the Original Date of Christmas, chronicon.net, archived from the original on March 3, 2013, retrieved December 29, 2018. Schmidt is translator of Hippolytus of Rome: Commentary on Daniel and 'Chronicon'.
