Russian Professor Andrei Kuin published a second volume of the book entitled "The Unsolved Mysteries of Bulgaria".
He graduated from the prestigious Moscow State Institute of International Relations and the Orthodox Spiritual Academy "St. St. Cyril and Methodius".
The book actually deals with controversial historical issues that Bulgarian historians have furiously arguing with historians from neighboring and more distant states. Quinn stands firm behind all Bulgarians, not because they are Bulgarian, but because that is the historical truth, as he himself writes.
In other words, for him and for his numerous readers, the first book of the author came out in Russian in hundreds of thousands of copies and quickly exhausted. We learn from it that Cyril and Methodius are Bulgarians and the Cyrillic alphabet was created in Pliska, at the command of Prince Boris I and the rest of the seven-year-olds. The first volume of the book underwent five editions.