1. Albouy, V., Godefroy, P., & Lollivier, S. (2010). Measuring quality of life. INSEE, 2010. Available at http://www.insee.fr/en/ffc/docs_ffc/ref/FPORSOC.pdf#page3 .
2. Chanques, G., Viel, E., Constantin, J.-M., Jung, B., de Lattre, S., Carr, J., et al. (2010). The measurement of pain in intensive care unit: Comparison of 5 self-report intensity scales. Pain, 151, 711–721. doi: 10.1016/j.pain.2010.08.039 .
3. Leary, T., Ridley, S., Burchett, K., Kong, A., Crispin, P., & Wright, M. (2002). Assessing critical care unit performance: A global measure using graphical analysis. Anaesthesia, 57, 751–755. doi: 10.1046/j.1365-2044.2002.02692.x .
4. Mosley, H., & Mayer, A. (1999). Benchmarking national labour market performance: A radar chart approach. Report prepared for the European Commission, Directorate-General V, Employment, Industrial Relations and Social Affairs (DG V/A2), March, 1999, ISSN 1011-9523. Available at http://bibliothek.wzb.eu/pdf/1999/i99-202.pdf .
5. Plantenga, J., & Hansen, J. (1999). Assessing equal opportunities in the European Union. International Labour Review, 138(4), 351–379. doi: 10.1111/j.1564-913X.1999.tb00393.x .