1. Aerts, D., Apostel, L., De Moor, B., Hellemans, S., Maex, E., Van Belle, H., & Van der Veken, J. (1994). Worldviews: From fragmentation to integration. Brussels Free University, Belgium.
2. Allport, G. W. (1955). Becoming: Basic considerations for a psychology of personality (Vol. 20). Yale University Press.
3. Averill, J. R., Catlin, G., & Chon, K. K. (1990). Rules of hope: Recent research in psychology. Springer.
4. Averill, J. R., & Sundararajan, L. (2005). Hope as rhetoric: Cultural narratives of wishing and coping. In J. Eliott (Ed.), Interdisciplinary perspectives on hope (pp. 133–165). Nova Science.
5. Beck, A. T. (1974). The development of depression: A cognitive model. In R. Friedman & M. Katz (Eds.), Psychology of depression: Contemporary theory and research. Winston.