1. Altrogge, G. (1996): Investition, 4. Aufl., München.
2. Anderson, E.W./Fornell, C./Lehmann, D.R. (1994): Customer Satisfaction, Market Share and Profitability. Findings from Sweden, in: Journal of Marketing, Vol. 58, No. 3, S. 53–66.
3. Anderson, E.W./Fornell, C./Rust, R.T. (1997): Customer Satisfaction, Productivity and Profitability. Differences between Goods and Services, in: Marketing Science, Vol. 16, No. 2, S. 129–146.
4. Arnold, W.W.; Plan, J.M. (1993): The Human Touch, New York.
5. Atkinson, H./Hamburg, J./Ittner, C. (1994): Linking Quality to Profits. Quality-Based Cost Management, Milwaukee.