APA (7th ed.) Citation

Helmke, M., Hudson, A., & Hudson, P. (2012). Ubuntu unleashed (2012 ed.). Sams Pub.

Chicago Style (17th ed.) Citation

Helmke, Matthew, Andrew Hudson, and Paul Hudson. Ubuntu Unleashed. 2012 ed. Indianapolis, Ind: Sams Pub, 2012.

MLA (9th ed.) Citation

Helmke, Matthew, et al. Ubuntu Unleashed. 2012 ed. Sams Pub, 2012.