1. A variance explanation paradox: When a little is a lot;Abelson;Psychological Bulletin,1985
2. American Sleep Disorders Association. (1990). International classification of sleep disorders: Diagnostic and coding manual. Diagnostic Classification Steering Committee, Thorpy MJ, Chairman. Rochester, Minnesota: American Sleep Disorders Association.
3. Diagnostic and statistical manual of mental disorders,1994
4. Diagnostic and statistical manual of mental disorders,2000
5. American Sleep Disorders Association. (1990). International classification of sleep disorders: Diagnostic and coding manual. Rochester, MN.