Intellectual quiz.

The answer is correct; they are Old Believers, and the precise term is Old Ritualists. I didn't quite understand what the USSR had to do with it, but that's what the comment to the question said. I think it's that in the USSR, due to the lack of paper, they used newspapers, and when paper became available, they remained true to the old "faith." However, I only understood the comment vaguely, but we took this question. Fireball, come join our team! Added 1 minute later Not Fireball, you're the only one who figured it out, and you did it right away... Come to Rostov!