Enge, E., Spencer, S., & Stricchiola, J. C. (2015). The Art of SEO: Mastering search engine optimazion (Third Edition.). O'Reilly.
Chicago-viite (17. p.)Enge, Eric, Stephan Spencer, ja Jessie C. Stricchiola. The Art of SEO: Mastering Search Engine Optimazion. Third Edition. Beijing: O'Reilly, 2015.
MLA-viite (9. p.)Enge, Eric, et al. The Art of SEO: Mastering Search Engine Optimazion. Third Edition. O'Reilly, 2015.
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