1. Alford, P. (1999). Database Marketing in Travel and Tourism, Travel and Tourism Analyst, 1,87–105.
2. Bauer, H. Grether, M. and Leach M. (1999). Customer Relations through the Internet, Working paper, Manneheim University,1–18.
3. Bonn, M. Fun, H. L. and Susskind A, (1999). Predicting a Behavioural Profile for Pleasure Travellers on the Basis of Internet Use Segmentation, Journal of Travel Research, 37, May 1999, 333–340.
4. Bly, R., Felt, M., Roberts, S. (2000). Internet Direct Mail, New York, McGraw Hill.
5. Brady, M., Saren M., Tzokas, N. (2002). Integrating Information Technology into Marketing Practice-the IT Reality of Contemporary Marketing Practice, Journal of Marketing Management, 18,(516),555–578.