Cita APA (7a ed.)

Warren, R. P., & Clark, W. B. (2015). Selected Letters of Robert Penn Warren: The Apprentice Years 1924-1934. Project Muse.

Cita Chicago Style (17a ed.)

Warren, Robert Penn, y William Bedford Clark. Selected Letters of Robert Penn Warren: The Apprentice Years 1924-1934. Baltimore, Maryland: Project Muse, 2015.

Cita MLA (8a ed.)

Warren, Robert Penn, y William Bedford Clark. Selected Letters of Robert Penn Warren: The Apprentice Years 1924-1934. Project Muse, 2015.