Frassetto (2013), pp. 506–507. (EN) Michael Frassetto, The Early Medieval World: From the Fall of Rome to the Time of Charlemagne, Vol 1. (A–K), Santa Barbara, CA, ABC-CLIO, 2013, OCLC931447923.
Frassetto (2013), p. 507. (EN) Michael Frassetto, The Early Medieval World: From the Fall of Rome to the Time of Charlemagne, Vol 1. (A–K), Santa Barbara, CA, ABC-CLIO, 2013, OCLC931447923.