1. Amarach, Search Engine Usage in Ireland - The Facts & Figures, Statistical Analysis (March 2007),
http://www.redcardinal.ie/search-engine-optimisation/23-03-2007/search-engine-statistics-ireland/#internet-usage-ireland
(accessed May 12th, 2007)
2. Asdemir, K., Yahya, M.: Legal and Strategic Perspectives on Click Measurement (2006),
http://www.sempo.org/learning_center/editorials/clickmeasurement.pdf
(accessed December 26th, 2006)
3. Boughton, B.: Search Engine Marketing. Perspectives in Business (2005),
http://www.stedwards.edu/business/pdf/PerspectivesV0201_06.pdf
(accessed December 12th, 2006)
4. Browne, G., Pitts, M., Weatherbe, J.: Cognitive stopping rules for terminating information search in online tasks. MIS Quarterly 31(1), 89–104 (2007)
5. Dawson, A., Hamilton, V.: Optimising metadata to make high-value content more accessible to Google users. Journal of Documentation 62(3), 307–327 (2006)