Khirina, G. and Savchenko, A. 2022. 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, (Dec. 2022), 45-50. DOI:https://doi.org/10.26565/2227-6505-2022-35-05.