1. Abdel-Khalek, A. M. (2006). Measuring happiness with a single item scale. Social Behavior and Personality: An International Journal, 34(2), 139–150. doi: 10.2224/sbp.2006.34.2.139 .
2. Anderson, A. R., & Havsy, L. (2001). Check & connect: an examination of the middle school transition. Washington, DC: Paper presented at the annual meeting of the National Association of School Psychologists.
3. Antaramian, S. P., Huebner, E. S., & Valois, R. F. (2008). Adolescent life satisfaction. Applied Psychology: An International Review, 57, 112–126. doi: 10.1111/j.1464-0597.2008.00357.x .
4. Argyle, M. (1993). Psicología y calidad de vida. [Psychology and quality of life]. Intervención Psicosocial, 2(6), 5–15.
5. Baltatescu, S. (2006). Comparative results and psychometric properties of the Personal Well-Being Index-Romania (old and new versions) with an adolescent sample- a preliminary analysis. Retrieved from http: www.sergiubaltatescu.info/content/comparativePWI website.