In my report I will present two theses. One is about Prince Mikhail Andreyevich Obolensky and his work to reveal and preserve the knowledge about the books of our Golden Age, sent to Kievan Rus by Presbyter Gregory on the order of Tsar Simeon the Great. The other reason for this, as it is related to the cultural heritage of Varna and the Black Sea region, is the presence of the excavations of a monastery known as the Holy Virgin, from the time of the kings Boris, his son Tsar Simeon, and grandson Tsar Peter, located on a terrace on the high part of the southern slope of Frangata, north of the city of Varna. In it, in addition to the uncovered remains of the buildings that are usual for such places, there is also a building known as the scriptorium, where the books that are known under the name of the Books of Our Golden Age were translated, written, illustrated, and shaped. During the time of the monastery's existence, until it fell under a landslide, before its discovery in the past century, no other such facility is known to have existed anywhere in the world.
М. А. Оболенский: Нѣсколько слов о первоначальной русской лѣтописи. V Sẏnodalʹnoĭ tip., 1870: Оригиналът е от Нюйоркската обществена библиотека. Цифровизирана на 24.4.2008.
Анна Хилкова „Изследования и заметки княза М. А. Оболенскаго по русскимъ и славянскимъ древностямъ“, Санкт Петербургъ, 1875
Людмила B. Горина (Московский государственный университет) «История Болгарии в трудах князя М.А. Оболенского» «macedonia.kroraina.com›tschilingirov/rus/gorina_