Vogt 1923, pp. 117–118. Vogt, Albert (1923). "The Macedonian Dynasty from 976 to 1057 A.D.". The Cambridge Medieval History, Vol. IV: The Eastern Roman Empire (717–1453). Cambridge: Cambridge University Press. pp. 83–118. OCLC895446365.
Vogt 1923, p. 118. Vogt, Albert (1923). "The Macedonian Dynasty from 976 to 1057 A.D.". The Cambridge Medieval History, Vol. IV: The Eastern Roman Empire (717–1453). Cambridge: Cambridge University Press. pp. 83–118. OCLC895446365.