1. Corcoran, B. & Wals, A.E. (1999). (eds.) Higher Education and the Challenges of Sustainability. NY: Springer.
2. Hart, R.A. (1997). Children's Participation: The Theory and Practice of Involving Young Citizens in Community Development and Environmental Care. London: Routledge.
3. Dombrovskis, V., Guseva, S., & Murasovs, V. (2011). Motivation to Work and the Syndrome of Professional Burn-out among Teachers in Latvia. Procedia Social and Behavioral Sciences. ICEEPSY 2011, 29, 98-106.
4. Erlandson, O.A. 8 Pastor, M.C. (1981). Teacher Motivation, Job Satisfaction, and Alternatives-Directions for Principals. NASSPBulletin, 5-9.
5. Heckhausen, J. & Heckhausen, H. (2010). Motivation und Handeln (4.Aufl.). Berlin, Heidelberg, New York: Springer.