prefix sioc: <http://rdfs.org/sioc/ns#> prefix sioct: <http://rdfs.org/sioc/types#> prefix ann: <http://www.w3.org/2000/10/annotation-ns#> prefix dct: <http://purl.org/dc/elements/1.1/> select * where { ?forum a sioct:Calendar. ?forum sioc:container_of ?post. optional{?post dct:title ?title}. optional {?post ann:hasAnnotation ?hn }. optional {?hn ann:annotates ?annotates } . optional {?hn ann:author ?author } . optional {?hn ann:body ?body } . optional {?hn ann:created ?created } . optional {?hn ann:modified ?modified }. }