Enge, E., Spencer, S., & Stricchiola, J. C. (2015). The Art of SEO: Mastering search engine optimazion (Third Edition.). O'Reilly.
Chicago-referens (17:e uppl.)Enge, Eric, Stephan Spencer, och Jessie C. Stricchiola. The Art of SEO: Mastering Search Engine Optimazion. Third Edition. Beijing: O'Reilly, 2015.
MLA-referens (9:e uppl.)Enge, Eric, et al. The Art of SEO: Mastering Search Engine Optimazion. Third Edition. O'Reilly, 2015.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.