Columbia subject headings:
Authors, Russian--20th century--Biography.
Ivask, I︠U︡riĭ.
Harvard subject headings:
Authors, Russian--20th century--Biography
Ivask, I͡Uriĭ
Ivask, I︠U︡riĭ--Biography.
Princeton subject headings:
Authors, Russian--20th century--Biography.
Ivask, I︠U︡riĭ.