On November 21, 2023, the presentation of the book "Marin Drinov: Letters, telegrams, detailed notes, 1859–1905" took place in Sofia. This publication marks the first comprehensive collection of the epistolary legacy of the distinguished Bulgarian historian and public figure, Professor Maryna Drynova (1838–1906), who served at Kharkiv University. The compilation is the result of years of collaborative efforts between Bulgarian and Ukrainian researchers to identify, annotate, and prepare for publication letters, telegrams, and report notes that shed light on Drinov's scientific, teaching, public activities, and private life. Professor Serhii Posokhov and Assistant Professor Viktoriia Ivashchenko served as compilers from the Ukrainian side, with project coordination by Professor Mykhailo Stanchev. The book presentation was attended by the heads of the National Academy of Sciences, including Academician Vasil Nikolov, along with other Bulgarian scientists. Representatives from Kharkiv University, Mykhailo Stanchev, and Serhii Strashnyuk, as well as Honorary Doctors of Kharkiv National University, Academician Ivan Yukhnovsky and Volodymyr Salenkov, were also present.