APA (7th ed.) Citation

Santayana, G., Holzberger, W. G., Jr, H. J. S., & Wokeck, M. S. (2004). The Letters of George Santayana, Book Six, 1937–1940: The Works of George Santayana, Volume V.

Chicago Style (17th ed.) Citation

Santayana, George, William G. Holzberger, Herman J. Saatkamp Jr, and Marianne S. Wokeck. The Letters of George Santayana, Book Six, 1937–1940: The Works of George Santayana, Volume V. 2004.

MLA (9th ed.) Citation

Santayana, George, et al. The Letters of George Santayana, Book Six, 1937–1940: The Works of George Santayana, Volume V. 2004.