1. Dominiguez, T.: How Much of The Internet is Hidden. Seeker, 2 Sept 2015
2. Pavalam, S.M., Kashmir Raja, S.V., Akorli, F.K., Jawahar, M.: A survey of web crawler algorithms. Int. J. Comput. Sci. Issues 8(6), no 1, 309–313 (2011)
3. Shen, A.: Algorithms and Programming: Problems and Solutions, 2nd edn. p. 135. Springer (2010)
4. Brin, S., Page, L.: Anatomy of a large scale hypertextual web search engine. In: Proceedings of the WWW Conference (2004)
5. Sivanandam, S.N., Deepa, S.N.: Introduction to Genetic Algorithms, p. 20. Springer (2008)