Cita APA (7a ed.)

Barker, K. (2012). CCNA Security 640-554 LiveLessons (Video Training) (1st edition.). Pearson IT Certification.

Cita Chicago Style (17a ed.)

Barker, Keith. CCNA Security 640-554 LiveLessons (Video Training). 1st edition. Pearson IT Certification, 2012.

Cita MLA (9a ed.)

Barker, Keith. CCNA Security 640-554 LiveLessons (Video Training). 1st edition. Pearson IT Certification, 2012.

Precaución: Estas citas no son 100% exactas.