APA (7th ed.) Citation

John, o. S., Butler, H. E., & Millor, W. J. (1955). Letters of John of Salisbury. T. Nelson.

Chicago Style (17th ed.) Citation

John, of Salisbury, H. E. Butler, and W. J. Millor. Letters of John of Salisbury. London ; New York: T. Nelson, 1955.

MLA (8th ed.) Citation

John, of Salisbury, et al. Letters of John of Salisbury. T. Nelson, 1955.