Kaymakamova, Miliana. “The Cult of the Bulgarian Tsar Peter (927–969) and the Driving Ideas of the Bulgarian Liberation Uprisings Against the Byzantine Rule in the 11th–12th Century”. The Bulgarian State in 927-969. The Epoch of Tsar Peter I: No. XXXIV, edited by Mirosław J. Leszka, Lodz University Press, 2018, pp. 457-78, https://doi.org/10.18778/8142-115-7.21.