Cita APA (7a ed.)

Safari Tech Books Online, Scott, C. A., Erwin, M. C., & Wolfe, P. C. (1999). Virtual private networks (2nd ed.). O'Reilly.

Cita Chicago Style (17a ed.)

Safari Tech Books Online, Charlie Author Scott, Mike Contributor Erwin, y Paul Contributor Wolfe. Virtual Private Networks. 2nd ed. [Place of publication not identified]: O'Reilly, 1999.

Cita MLA (9a ed.)

Safari Tech Books Online, et al. Virtual Private Networks. 2nd ed. O'Reilly, 1999.