^Florin Curta, Southeastern Europe in the Middle Ages, 500-1250, Cambridge University Press, 2006, ISBN9780521815390, p. 363.
^Panos Sophoulis, Banditry in the Medieval Balkans, 800-1500, Palgrave Macmillan, 2020, ISBN9783030559045, pp. 81–82.
^John Van Antwerp Fine, The Late Medieval Balkans: A Critical Survey from the Late Twelfth Century to the Ottoman Conquest, University of Michigan Press, 1994, ISBN0472082604, p. 29.
^Alexandru Madgearu, The Asanids: The Political and Military History of the Second Bulgarian Empire (1185-1280), BRILL, 2016, ISBN9789004333192, p. 110; 117; 158.