David, M. (2011). WordPress 3 search engine optimization: Optimize your Website for popularity with search engines. Packt Pub..
Chicago-viite (17. p.)David, Michael. WordPress 3 Search Engine Optimization: Optimize Your Website for Popularity with Search Engines. Olton, Birmingham: Packt Pub., 2011.
MLA-viite (9. p.)David, Michael. WordPress 3 Search Engine Optimization: Optimize Your Website for Popularity with Search Engines. Packt Pub., 2011.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.