Cita APA (7a ed.)

Enge, E., & Enge, E. (2009). The art of SEO (1st edition.). O'Reilly Media.

Cita Chicago Style (17a ed.)

Enge, Eric, y Eric Enge. The Art of SEO. 1st edition. Sebastopol, Calif.: O'Reilly Media, 2009.

Cita MLA (9a ed.)

Enge, Eric, y Eric Enge. The Art of SEO. 1st edition. O'Reilly Media, 2009.