Alldritt, Keith, W. B. Yeats: The Man and the Milieu, Clarkson Potter Publishers, 1997.

This is a very accessible study of the ways in which
Yeats carefully constructed his public image as poet,
nationalist, and literary activist. Alldritt explores the
ways in which Yeats's social environment contributed
to his identity.

Graves, Robert, The Common Asphodel: Collected Essays on Poetry, 1922-1949, Hamilton, 1949, pp. 186-88.

Graves's reading of Yeats's poem is one of the harshest
pieces of criticism written about it.

Jeffares, Norman A., W. B. Yeats: A New Biography, Farrar Straus Giroux, 1988.

This is Jeffares second biography of Yeats. His first
appeared just ten years after the poet's death. In this
biography, Jeffares charts the stages of Yeats's career,
telling the story of his turbulent personal and
public lives.