APA (7th ed.) Citation

Santayana, G., Holzberger, W. G., & Jr, H. J. S. (2003). The Letters of George Santayana, Book Four, 1928–1932: The Works of George Santayana, Volume V.

Chicago Style (17th ed.) Citation

Santayana, George, William G. Holzberger, and Herman J. Saatkamp Jr. The Letters of George Santayana, Book Four, 1928–1932: The Works of George Santayana, Volume V. 2003.

MLA (9th ed.) Citation

Santayana, George, et al. The Letters of George Santayana, Book Four, 1928–1932: The Works of George Santayana, Volume V. 2003.