1. Cicerchia, A. (1996). Indicators for the measurement of the quality of urban life: What is the appropriate territorial dimension? Social Indicators Research, 39, 321–358.
2. Cicerchia, A. (1999). Measures of optimal centrality: Indicators of city effect and urban overloading. Social Indicators Research, 46, 273–299.
3. Cramer, V., Torgersen, S., & Kringler, E. (2004). Quality of life in a city: the Effect of population density. Social Indicators Research, 69, 103–116.
4. Directorate-General for Regional Policy of the European Commission – Eurostat. Urban audit, Bruxelles: European Commission (continuously updated: http://www.urbanaudit.org/
5. Elgin, D., Thomas, T., Logothetti, T., & Cox, S. (1974). City size and the quality of life. An analysis of policy implications and continued population concentration. Stanford: National Science Foundation – Research Applied to National Needs Program, The Stanford Research Institute.