Columbia subject headings:
Yeats, W. B. (William Butler), 1865-1939--Versification.
Harvard subject headings:
Yeats, W. B. (William Butler), 1865-1939--Versification.
Princeton subject headings:
English language--20th century--Versification.
Yeats, W. B. (William Butler), 1865-1939--Versification.