title: Cross-cultural epidemiology of daytime sleepiness: universality, diversity and definition issues.
authors.forename: Y K
authors.initials: YK
authors.lastname: Wing
authors.forename: L
authors.initials: L
authors.lastname: Chen
mesh_terms: D003431:Cross-Cultural Comparison; D020920:Dyssomnias / Q000208:ethnology*; D006801:Humans; D015995:Prevalence; D012307:Risk Factors