title: Quantitative and qualitative aspects of sleep in young self-selected four-shift workers.
mesh_terms: D000204:Activity Cycles; D000328:Adult; D000367:Age Factors; D002940:Circadian Rhythm; D006801:Humans; D009787:Occupational Medicine; D012890:Sleep / Q000502:physiology*; D013997:Time Factors; D014937:Work