Madgear,u Alexandru (2016) The Asanids: politicary and military history of the Second Bulgarian Empire 1185–1280 33387: BRILL ISBN 978-9-004-32501-2.
Madgearu, Alexandru (2016). The Asanids: The Political and Military History of the Second Bulgarian Empire, 1185–1280. BRILL. ISBN 978-9-004-32501-2.