as a dude who was born and lived his whole life in russia, i gotta tell you that most of the samples are not from russian music. Soviet bands, maybe. But most of the samples are from czech, yugoslavian, bulgarian, slovenian, etc music. Slavic languages get confused by people a lot, because of the similarities that they share, there are a lot of common words in these languages.
Though it was nice when my dad heard the sample from the song that he used to listen to a lot when he was young.