APA (7th ed.) Citation

Mui, L., Quercia, V., & Darwin, I. F. (1994). X user tools. O'Reilly.

Chicago Style (17th ed.) Citation

Mui, Linda, Valerie Quercia, and Ian F. Darwin. X User Tools. Sebastopol, California: O'Reilly, 1994.

MLA (9th ed.) Citation

Mui, Linda, et al. X User Tools. O'Reilly, 1994.