APA (7th ed.) Citation

Safari Tech Books Online, Udell, J. A., & O'Reilly, T. (1999). Practical internet groupware. O'Reilly.

Chicago Style (17th ed.) Citation

Safari Tech Books Online, Jon Author Udell, and Tim O'Reilly. Practical Internet Groupware. [Place of publication not identified]: O'Reilly, 1999.

MLA (9th ed.) Citation

Safari Tech Books Online, et al. Practical Internet Groupware. O'Reilly, 1999.