Columbia subject headings:
Blok, Aleksandr Aleksandrovich, 1880-1921.
Harvard subject headings:
Blok, Aleksandr Aleksandrovich, 1880-1921
Blok, Aleksandr Aleksandrovich, 1880-1921--Criticism and interpretation.
Princeton subject headings:
Blok, Aleksandr Aleksandrovich, 1880-1921.