1. American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.
2. Gresham, F. M., & Elliot, S. N. (1990). The social skills rating system (SSRS). Circle Pines, MN: American Guidance Service.
3. Heward, W. L. (2003). Exceptional children: An introduction to special education (7th ed.). CITY, NJ: Merrill Prentice-Hall.
4. Lee, H. C. (2003, February 27). Teen suicides: Relationship problems the main cause. The Straits Times, p. 4.
5. Lee, L. (2004, September 24). Teachers get special needs training. The Straits Times, p. 1.