Is primary topic of
Select children
Text
PREFIX  dct:  <http://purl.org/dc/terms/>
PREFIX  foaf: <http://xmlns.com/foaf/0.1/>
PREFIX  sioc: <http://rdfs.org/sioc/ns#>

SELECT DISTINCT  ?child ?title ?thing
WHERE
  { GRAPH ?childGraphGraph
      {   { ?child  sioc:has_parent  ?this }
        UNION
          { ?child  sioc:has_container  ?this }
      }
    GRAPH ?childGraph
      { ?child  a                     ?Type
        OPTIONAL
          { ?child  dct:title  ?title }
        OPTIONAL
          { ?child  foaf:primaryTopic  ?thing }
      }
  }
Primary topic
Select children