@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/Duke_Longitudinal_Studies>
  skos:definition "The Duke Longitudinal Studies of Aging, initiated in 1955, consist of two separate studies. The first longitudinal study began in 1955 with 271 persons 60 to 90 years of age. [Source: <a href=\"https://sk.sagepub.com/reference/aging/n88.xml\" target=\"_blank\" data-id=\"to-sk\">Encyclopedia of Health &amp; Aging; Duke Longitudinal Studies</a>]"@en ;
  skos:broader <https://concepts.sagepub.com/social-science/concept/studies_of_aging> ;
  skos:prefLabel "Duke Longitudinal Studies"@en ;
  a skos:Concept .

<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/Duke_Longitudinal_Studies> .

<https://concepts.sagepub.com/social-science/concept/studies_of_aging>
  skos:prefLabel "studies of aging"@en ;
  a skos:Concept ;
  skos:narrower <https://concepts.sagepub.com/social-science/concept/Duke_Longitudinal_Studies> .