Analysis of information sources in references of the Wikipedia article "Double-headed eagle" in English language version.
{{cite book}}: CS1 maint: location missing publisher (link). "Ο φωτισμένος αυτός Αυτοκράτορας καταγόταν από Οίκο της Παφλαγονίας, όπου στην πόλη Γάγγρα υπήρχε ο θρύλος της ύπαρξης φτερωτού αετόμορφου και δικέφαλου θηρίου (γνωστού ως Χάγκα), το οποίο και κοσμούσε το θυρεό του κτήματος της οικογένειάς του στην Καστάμονη." It is unclear where Zapheiriou's term Haga (Χάγκα) is taken from; it does not appear to find further reflection in scholarly literature but it was adopted by historical fiction author Gordon Doherty in his Strategos: Island in the Storm (2014), see note on p. 390: "One theory is that the symbol was adopted from the many ancient Hittite rock carvings of the mythical Haga found throughout Anatolia."The eagle was a common heraldic symbol for many Albanian dynasties in the Late Middle Ages and came to be a symbol of the Albanians in general. It is also said to have been the flag of Skanderbeg.... As a symbol of modern Albania, the flag began to be seen during the years of the national awakening and was in common use during the uprisings of 1909–1912. It was this flag that Ismail Qemal bey Vlora raised in Vlora on 28 November 1912 in proclaiming Albanian independence.