. Archaeology Magazine (§ Tuscan Excalibur?)
. The Guardian (§ Tuscany's Excalibur, 2001)
. Fasciculi Archaeologiae Historicae (Chodyński, 2014)
. Wikipedia (§ Excalibur, Robert de Boron, Caledfwlch)
. Encyclopaedia Britannica (§ Excalibur)
. Garlaschelli, Università di Pavia(Reliquie e reperti... Rotonda di Montesiepi)