8Berger, Paul, D, and Nada 1, Nasr, Customer lifetime value:marketing model and applicantions, Journalof Interactive Marketing, 1998.
9Gupta Sunil, Donald R. Lehmann, Jennifer Ames Stuart, Valuing customers. Journal of Marketing Research, 41(1), 2004, p. 8.
10Hyunseok Hwanag,Taesoo Jung, Euiho suh. An LTV Model and Customer Segmentation Based on Customer Value: ACase Study on the Wireless Telecommunication Industry. Expert Systems with Applications, (26), 2004, pp. 181-188.