Налівайко, Андрій. “The Genesis of the Struggle for Investiture Between Secular and Spiritual Power in England in L. Berkut’s Studies”. Antiquities of Lukomorie, no. 1 (February 28, 2022): 5-13. Accessed April 2, 2025. http://lukomor.mosk.mksat.net/index.php/lukomor/article/view/133.