APA (7th ed.) Citation

Jones, J. P., Porter, H., Sanborn, F. B., & Bixby, W. K. Letters of John Paul Jones.

Chicago Style (17th ed.) Citation

Jones, John Paul, Horace Porter, F. B. Sanborn, and William K. Bixby. Letters of John Paul Jones.

MLA (9th ed.) Citation

Jones, John Paul, et al. Letters of John Paul Jones.