APA (7th ed.) Citation

Smith, R. W. (2004). Linux+ study guide (2nd ed.). Sybex.

Chicago Style (17th ed.) Citation

Smith, Roderick W. Linux+ Study Guide. 2nd ed. San Francisco, CA ; London: Sybex, 2004.

MLA (9th ed.) Citation

Smith, Roderick W. Linux+ Study Guide. 2nd ed. Sybex, 2004.