Olsen, Martin (20 May 2010). "Maximizing PageRank with New Backlinks". In Diaz, Josep; Calamoneri, Tiziana (eds.). Algorithms and Complexity: 7th International Conference, CIAC 2010, Rome, Italy, May 26–28, 2010, Proceedings. Berlin: Springer Science & Business Media. p. 37. ISBN978-3-642-13072-4. OCLC873382847.
Olsen, Martin (20 May 2010). "Maximizing PageRank with New Backlinks". In Diaz, Josep; Calamoneri, Tiziana (eds.). Algorithms and Complexity: 7th International Conference, CIAC 2010, Rome, Italy, May 26–28, 2010, Proceedings. Berlin: Springer Science & Business Media. p. 37. ISBN978-3-642-13072-4. OCLC873382847.