Cita APA (7a ed.)

Johnson, A. (2008). 31 Days Before Your CCNA Exam: A day-by-day review guide for the CCNA 640-802 exam (2nd edition.). Pearson Education.

Cita Chicago Style (17a ed.)

Johnson, Allan. 31 Days Before Your CCNA Exam: A Day-by-day Review Guide for the CCNA 640-802 Exam. 2nd edition. S.l.: Pearson Education, 2008.

Cita MLA (9a ed.)

Johnson, Allan. 31 Days Before Your CCNA Exam: A Day-by-day Review Guide for the CCNA 640-802 Exam. 2nd edition. Pearson Education, 2008.