diff --git a/sparql/find_text.rq b/sparql/find_text.rq
index 1a510c7..f134984 100644
--- a/sparql/find_text.rq
+++ b/sparql/find_text.rq
@@ -4,7 +4,7 @@
 
 #PREFIX bif: <http://www.openlinksw.com/schemas/bif#>  # for Virtuoso
 
-SELECT ?s ?p ?o
+SELECT DISTINCT ?s ?p ?o
 WHERE {
     ?s ?p ?o .
     ?o <bif:contains> ?_text .
diff --git a/sparql/find_uri.rq b/sparql/find_uri.rq
index ff0aedd..6e596b4 100644
--- a/sparql/find_uri.rq
+++ b/sparql/find_uri.rq
@@ -4,7 +4,7 @@
 
 #PREFIX bif: <http://www.openlinksw.com/schemas/bif#>  # for Virtuoso
 
-SELECT ?s ?p (?_uri_iri AS ?URI)
+SELECT DISTINCT ?s ?p (?_uri_iri AS ?URI)
 WHERE {
     ?s ?p ?_uri_iri .
 }
diff --git a/sparql/get_children_ids.rq b/sparql/get_children_ids.rq
index 2f043fe..f8dbf47 100644
--- a/sparql/get_children_ids.rq
+++ b/sparql/get_children_ids.rq
@@ -6,7 +6,7 @@ PREFIX dcat: <http://www.w3.org/ns/dcat#>
 PREFIX r3d: <http://www.re3data.org/schema/3-0#>
 #PREFIX bif: <http://www.openlinksw.com/schemas/bif#>  # for Virtuoso
 
-SELECT (?o AS ?ChildrenID)
+SELECT DISTINCT (?o AS ?ChildrenID)
 WHERE {
     { ?_id_iri r3d:dataCatalog ?o . }
     UNION