Dyadyshcheva-Rosovetska, Julia. “Stylistic Features of Cyrillic Graffiti of the Pre-Mongol Period in Kyiv St. Sophia’s Cathedral ”. Current Issues of Ukrainian Linguistics: Theory and Practice, no. 36, July 2018, pp. 19-37, https://doi.org/10.17721/APULTP.2018.36.19-37.