Columbia subject headings:
Russian language--Aspect--Congresses.
Russian language--Verb--Congresses.
Slavic languages--Aspect--Congresses.
Slavic languages--Verb--Congresses.
Harvard subject headings:
Russian language--Aspect--Congresses.
Russian language--Verb--Congresses.
Slavic languages--Aspect--Congresses.
Slavic languages--Verb--Congresses.
Princeton subject headings:
Russian language--Aspect--Congresses.
Russian language--Verb--Congresses.
Slavic languages--Aspect--Congresses.
Slavic languages--Verb--Congresses.