Complex sentence: The proceedings were framed by denunciations in the media, headed by the newspapers "Pravda", "Izvestia" and "Literaturnaya Gazeta", which also published collective condemnation letters by Soviet citizens.
Split into simpler sentences: The proceedings were framed by denunciations in the media, headed by the newspapers "Pravda", "Izvestia" and "Literaturnaya Gazeta". The papers also published collective condemnation letters by Soviet citizens.