Columbia subject headings:
Likhachev, D. S. (Dmitriĭ Sergeevich)--Congresses.
Harvard subject headings:
Likhachev, D. S. (Dmitriĭ Sergeevich)--Anniversaries, etc.
Likhachev, D. S. (Dmitriĭ Sergeevich)--Congresses.
Princeton subject headings: