Cita APA (7th ed.)
Ledford, J. L. (2008). SEO: Search engine optimization bible. Wiley ; John Wiley [distributor].
Cita Chicago (17th ed.)
Ledford, Jerri L. SEO: Search Engine Optimization Bible. Hoboken, N.J. : Chichester: Wiley ; John Wiley [distributor], 2008.
Cita MLA (9th ed.)
Ledford, Jerri L. SEO: Search Engine Optimization Bible. Wiley ; John Wiley [distributor], 2008.
Atenció: Aquestes cites poden no estar 100% correctes.