Columbia subject headings:
Harvard subject headings:
Civilization--History--Congresses.
Likhachev, D. S. (Dmitriĭ Sergeevich)--Congresses.
Soviet Union--Civilization--Congresses.
Princeton subject headings:
Art and society.
Likhachev, D. S. (Dmitriĭ Sergeevich)
Literature and society.
Literature, Medieval--History and criticism.
Literature--History and criticism.