Shreves, R. (2012). Drupal search engine optimization: Drive people to your site with this supercharged guide to Drupal SEO. Packt Pub..
Chicago-referens (17:e uppl.)Shreves, Ric. Drupal Search Engine Optimization: Drive People to Your Site with This Supercharged Guide to Drupal SEO. Birmingham: Packt Pub., 2012.
MLA-referens (9:e uppl.)Shreves, Ric. Drupal Search Engine Optimization: Drive People to Your Site with This Supercharged Guide to Drupal SEO. Packt Pub., 2012.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.