@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

<http://www.irandoc.acir/onto/irandoc/CHMTR000023>
  skos:broader <http://www.irandoc.acir/onto/irandoc/CHMTR000034> ;
  skos:prefLabel "اكسیدهای نیتروژن"@fa, "nitrogen oxides"@en ;
  a <http://www.irandoc.ac.ir/onto/irandoc-meta/Concept>, skos:Concept .

<http://www.irandoc.acir/onto/irandoc/CHMTR000034>
  skos:prefLabel "آلاینده‌های هوا"@fa, "air pollutants"@en ;
  a <http://www.irandoc.ac.ir/onto/irandoc-meta/Concept>, skos:Concept ;
  skos:narrower <http://www.irandoc.acir/onto/irandoc/CHMTR000023> .