Columbia subject headings:
Shelley, Percy Bysshe, 1792-1822.
Yeats, W. B. (William Butler), 1865-1939.
Harvard subject headings:
Shelley, Percy Bysshe, 1792-1822--Influence.
Yeats, W. B. (William Butler), 1865-1939--Knowledge--Literature.
Princeton subject headings:
Shelley, Percy Bysshe, 1792-1822.
Yeats, W. B. (William Butler), 1865-1939.