Length and distribution of sleep and the intrasleep process.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D012890:Sleep; D012894:Sleep Stages; D012895:Sleep, REM