[1] Internet Resource, “Search engine user attitudes”, April-May 2004, www.iProspect.com
[2] Internet Resource, “IAB internet advertising revenue report,” http://www.iab.net/media/file/IAB_PWC_2008_6m.pdf.
[3] Internet resource, “comScore releases september U.S. search engine rankings,” www.comscore.com, http://www.comscore.com/press/release.asp?press=1805.
[4] B. Jansen, “Click fraud,” IEEE Computer, Vol. 40, No. 7, pp. 85-86.
[5] Internet resource, “Google adwords online introduction,” http://adwords.google.com/support/bin/answer.py?answer=19657&topic=342.
[6] B. Jansen and T. Mullen, “Sponsored search: An overview of the concept, history, and technology,” International Journal of Electronic Business, Vol. 6, No 2, pp. 114-131, 2008.
[7] J. Feng, H. K. Bhargava, and D. M. Pennock, “Implementing sponsored search in web search engines: Computational evaluation of alternative mechanisms,” INFORMS Journal on Computing, Vol. 19, No. 1, pp. 137-148. Winter 2007.
[8] B. Edelman, M. Ostrovsky, and M. Schwarz, “Internet advertising and the generalized second-price auction: Selling billions of dollars worth of keywords,” American Economic Re-view, Vol. 97. No. 1. pp 242-259, March 2007.
[9] J. Feng, Z. M. Shen, and R. L. Zhan, “Ranked items auctions and online advertisement,” Production and Operation Management, Vol. 16. No. 4. pp. 510-522. July-August 2007.
[10] K. Asdemir, N. Kumar, and V. Jacob, “Internet advertising pricing models,” Technique report, School of Management, The University of Texas at Dallas, 2002.
[11] Y. Hu, “Performance-based pricing models in online ad-vertising,” Ph.D. dissertation, Massachusetts Institute of Technology, Cambridge, MA, 2005, AAT 0807658.
[12] T. A. Weber and Z. Zheng, “A model of search intermediaries and paid referrals,” Information Systems Research, Vol. 18, No. 4, pp. 414-437, December 2007.
[13] S. Kumar, M. Dawande, and V. S. Mookerjee, “Optimal scheduling and placement of internet banner advertisements,” IEEE Transactions on Knowledge and Data Engineering, Vol. 19, No. 11, pp. 1571-1584, November 2007.
[14] B. Edelman and M. Ostrovsky, “Strategic bidder behavior in sponsored search auctions,” Decision Support Systems, Vol. 43, No. 1, pp. 192-198.
[15] J. Feng and M. Zhang, “Price cycles in online advertising auctions,” Proceedings of the 26th International Conference on Information Systems (ICIS), Las Vegas, NV, December 2005.
[16] O. Ozlük and S. Cholette, “Allocating expenditures across keywords in search advertising,” Journal of Revenue and Pricing Management, Vol. 6, pp. 347-356.
[17] R. M. Dewan, M. L. Freimer, and J. Zhang, “Management and valuation of advertisement-supported web sites,” Journal of Management Information Systems, Vol. 19, No. 3, pp. 87-98, Winter 2002/2003.
[18] G. E. Fruchter and W. Dou, “Optimal budget allocation over time for keyword ads in web portals,” Journal of Op-timization Theory and Applications, Vol. 124, No. 1, pp. 157-174, January 2005.
[19] Internet resource, “Online newspaper viewership reaches record in 2007,” www.naa.org, http://www.naa.org/PressCenter/SearchPressReleases/2008/ Online-Newspaper-Viewership. aspx.