Cita APA (7a ed.)

Vachon, B. (2012). CCNA Security (640-554) Portable Command Guide (1st edition.). Pearson Education.

Cita Chicago Style (17a ed.)

Vachon, Bob. CCNA Security (640-554) Portable Command Guide. 1st edition. S.l.: Pearson Education, 2012.

Cita MLA (9a ed.)

Vachon, Bob. CCNA Security (640-554) Portable Command Guide. 1st edition. Pearson Education, 2012.