“The KGB and Perlustration of International Correspondence in the Ukrainian SSR: the Case of Roman Hryn: DOI: Https: doi.Org 10.17721 1728-2640.2026.162.14”. 2026. Bulletin of Taras Shevchenko National University of Kyiv. History 162 (1-2). https://history.bulletin.knu.ua/en/article/view/10342.