@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix isothes: <http://purl.org/iso25964/skos-thes#> .

<https://concepts.sagepub.com/social-science/concept/sleep_stages>
  skos:prefLabel "sleep stages"@en ;
  a skos:Concept ;
  skos:narrower <https://concepts.sagepub.com/social-science/concept/REM_sleep> .

<https://concepts.sagepub.com/social-science/concept/conceptgroup/concepts>
  a skos:Collection, isothes:ConceptGroup ;
  skos:prefLabel "concepts"@en ;
  skos:member <https://concepts.sagepub.com/social-science/concept/REM_sleep> .

<https://concepts.sagepub.com/social-science/concept/REM_sleep>
  skos:definition "The terms rapid eye movement (REM) and nonrapid eye movement (NREM) were first coined by William Dement in the 1950s; he went on to become a leader in the field of sleep research. REM sleep occurs in the fifth stage of sleep and is associated with dreaming. [Source: <a href=\"https://sk.sagepub.com/reference/behavioralsciences/n2177.xml\" target=\"_blank\" data-id=\"to-sk\">The SAGE Glossary of the Social and Behavioral Sciences; REM Sleep</a>]"@en ;
  skos:exactMatch <https://id.nlm.nih.gov/mesh/D012895.html> ;
  skos:broader <https://concepts.sagepub.com/social-science/concept/sleep_stages> ;
  skos:prefLabel "REM sleep"@en ;
  a skos:Concept .