References
- AMERICAN PSYCHIATRIC ASSOCIATION (1994). Diagnostic and statistical manual of mental disorders (4th edn). Washington, DC: American Psychiatric Association.
- GOLDBERG, D.P. & WILLIAMS, P. (1988). The user’s guide to the general health questionnaire. Slough: NFER-Nelson.
- WORLD HEALTH ORGANIZATION (1993). The ICD-10 classification of mental and behavioural disorders: diagnostic criteria for research. Geneva: WHO.