MIKLOŠÍK, Andrej. Trends in Search Engine Ranking of Selected Slovak Universities and SEO Performance Implicitly. In Journal of International Scientific Publications : Economy & Business. - Burgas : Science Events. ISSN 1314-7242, 2013, vol. 7, part 2, pp. 463-470 online. Dostupné na : <http://www.scientific-publications.net/download/economy-and-business-2013-2.pdf>