Khirina, Ganna, and Aliona Savchenko. “The Story of Three Letters. Spiritual Relay of the Generations. V. N. Karazin – E. I. Koltunovsky – M. F. Sumtsov”. V. N. Karazin Kharkiv National University Bulletin ‘History of Ukraine. Ukrainian Studies: Historical and Philosophical Sciences’ 35 (June 14, 2023): 45-50. Accessed November 28, 2023. https://periodicals.karazin.ua/uahistory/article/view/21860.