PREFIX sioc: <http://rdfs.org/sioc/ns#> PREFIX sioct: <http://rdfs.org/sioc/types#> PREFIX foaf: <http://xmlns.com/foaf/0.1/> CONSTRUCT { ?post foaf:maker ?maker . ?maker foaf:firstName ?fname . ?maker foaf:phone ?phone . } WHERE { ?forum a sioct:BookmarkFolder . ?forum sioc:container_of ?post. optional{ ?post foaf:maker ?maker }. optional{ ?maker foaf:firstName ?fname } . optional{ ?maker foaf:phone ?phone } . }