Joachim Whaley, Germany and the Holy Roman Empire: Volume I: Maximilian I to the Peace of Westphalia, 1493–1648 (2012), pp. 17–20Arxivləşdirilib 2017-02-11 at the Wayback Machine.
Lonnie R. Johnson, Central Europe: Enemies, Neighbors, Friends (1996), Oxford University Press, p. 23Arxivləşdirilib 2022-08-10 at the Wayback Machine.
Martin Arbage, "Otto I", in Medieval Italy: An EncyclopediaArxivləşdirilib 2020-10-01 at the Wayback Machine, Volume 2 (Routledge, 2004), p. 810: "Otto can be considered the first ruler of the Holy Roman empire, though that term was not used until the twelfth century."
While Charlemagne and his successors assumed variations of the title emperor, none termed themselves Roman emperor until Otto II in 983. Holy Roman EmpireArxivləşdirilib 2014-10-23 at the Wayback Machine, Encyclopædia Britannica Online. Retrieved 15 fevral 2014.
Joachim Whaley, Germany and the Holy Roman Empire: Volume I: Maximilian I to the Peace of Westphalia, 1493–1648 (2012), pp. 17–20Arxivləşdirilib 2017-02-11 at the Wayback Machine.
Lonnie R. Johnson, Central Europe: Enemies, Neighbors, Friends (1996), Oxford University Press, p. 23Arxivləşdirilib 2022-08-10 at the Wayback Machine.
While Charlemagne and his successors assumed variations of the title emperor, none termed themselves Roman emperor until Otto II in 983. Holy Roman EmpireArxivləşdirilib 2014-10-23 at the Wayback Machine, Encyclopædia Britannica Online. Retrieved 15 fevral 2014.
Martin Arbage, "Otto I", in Medieval Italy: An EncyclopediaArxivləşdirilib 2020-10-01 at the Wayback Machine, Volume 2 (Routledge, 2004), p. 810: "Otto can be considered the first ruler of the Holy Roman empire, though that term was not used until the twelfth century."
