title: [Not too much and not too little. How much sleep is optimal?].
authors.forename: Peter
authors.initials: P
authors.lastname: Stiefelhagen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002940:Circadian Rhythm; D015897:Comorbidity; D006970:Disorders of Excessive Somnolence / Q000401:mortality; D005858:Germany; D006801:Humans; D008017:Life Expectancy; D008875:Middle Aged; D011788:Quality of Life / Q000523:psychology*; D020181:Sleep Apnea, Obstructive / Q000401:mortality / Q000523:psychology; D012892:Sleep Deprivation / Q000401:mortality; D012893:Sleep Wake Disorders / Q000401:mortality* / Q000523:psychology*; D014851:Wakefulness