Millichap, J. R. (2009). Robert Penn Warren after Audubon: The work of aging and the quest for transcendence in his later poetry. Louisiana State University Press.

Millichap, Joseph R. Robert Penn Warren After Audubon: The Work of Aging and the Quest for Transcendence in His Later Poetry. Baton Rouge: Louisiana State University Press, 2009.

Millichap, Joseph R. Robert Penn Warren After Audubon: The Work of Aging and the Quest for Transcendence in His Later Poetry. Louisiana State University Press, 2009.