Stafford, William. The Darkness Around Us Is Deep: Selected Poems of William Stafford. Ed. Robert Bly. New York: Harper, 1993.
Thoreau, Henry David. Walden, Or, Life in the Woods. Boston: Shambhala, 1992.
Tillich, Paul. Theology of Culture. Oxford: Oxford University Press, 1959.
Untermeyer, Louis, ed. A Concise Treasury of Great Poems. New York: Simon and Schuster, 1942.
Vaughan-Lee, Llewellyn. Sufism: The Transformation of the Heart. Inverness, CA: The Golden Sufi Center, 1995.
Willey, Basil. Nineteenth Century Studies: Coleridge to Matthew Arnold. New York: Harper, 1966.
Yeats, W.B. Selected Poems and Two Plays. Ed. M.L. Rosenthal. New York: MacMillan, 1962.