diff --git a/build.gradle b/build.gradle
index 0fafbbd..fa43e60 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,5 +1,5 @@
 group 'org.doremus'
-version '0.5.1'
+version '0.6.0'
 
 apply plugin: 'java'
 apply plugin: 'application'
diff --git a/src/main/java/org/doremus/string2vocabulary/SKOSVocabulary.java b/src/main/java/org/doremus/string2vocabulary/SKOSVocabulary.java
index c51aaba..0f52e2e 100644
--- a/src/main/java/org/doremus/string2vocabulary/SKOSVocabulary.java
+++ b/src/main/java/org/doremus/string2vocabulary/SKOSVocabulary.java
@@ -4,23 +4,24 @@
 import org.apache.jena.vocabulary.RDF;
 import org.apache.jena.vocabulary.SKOS;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 public class SKOSVocabulary extends Vocabulary {
-  private Map<String, List<Resource>> substitutionMap;
-  private Map<String, List<Resource>> substitutionMapNoBrackets;
+  private final Map<String, Resource> substitutionMap;
+  private final Map<String, Resource> substitutionMapNoBrackets;
+  private final Map<String, Resource> substitutionMapPlain;
+  private final Map<String, Resource> substitutionMapPlainNoBrackets;
 
   public SKOSVocabulary(String name, Model model) {
     super(name, model);
 
     setSchemePathFromType(SKOS.ConceptScheme);
 
-    // Build a map
+    // Build maps
     substitutionMap = new HashMap<>();
     substitutionMapNoBrackets = new HashMap<>();
+    substitutionMapPlain = new HashMap<>();
+    substitutionMapPlainNoBrackets = new HashMap<>();
 
     // for each concept
     StmtIterator conceptIter =
@@ -31,83 +32,84 @@ public SKOSVocabulary(String name, Model model) {
       return;
     }
 
-    while (conceptIter.hasNext()) {
-      Resource resource = conceptIter.nextStatement().getSubject();
-      // get the labels
-      StmtIterator labelIterator = resource.listProperties(SKOS.prefLabel);
-      //for each label
-      while (labelIterator.hasNext()) {
-        Literal nx = labelIterator.nextStatement().getLiteral();
-        String value = norm(nx.getLexicalForm());
-        String valueNb = normNb(nx.getLexicalForm());
-        String lang = nx.getLanguage();
-        if (lang != null && !lang.isEmpty()){
-          value += "@" + nx.getLanguage();
-          valueNb += "@" + nx.getLanguage();
-        }
-
-        // get the list or create a new one
-        List<Resource> ls = substitutionMap.computeIfAbsent(value, k -> new ArrayList<>());
-        List<Resource> lsNb = substitutionMapNoBrackets.computeIfAbsent(valueNb, k -> new ArrayList<>());
-        // add it to the list
-        ls.add(resource);
-        lsNb.add(resource);
+    while (conceptIter.hasNext())
+      processConcept(conceptIter.nextStatement().getSubject());
+  }
+
+  private void processConcept(Resource resource) {
+    // get the labels
+    StmtIterator labelIterator = resource.listProperties(SKOS.prefLabel);
+    //for each label
+    while (labelIterator.hasNext()) {
+      Literal nx = labelIterator.nextStatement().getLiteral();
+      String value = norm(nx.getLexicalForm());
+      String valueNb = normNb(nx.getLexicalForm());
+
+      // add the value or - if already there - keep the best one
+      putKeepBest(value, resource, substitutionMapPlain);
+      putKeepBest(valueNb, resource, substitutionMapPlainNoBrackets);
+
+      // now, manage the lang tag
+      String lang = nx.getLanguage();
+      if (lang != null && !lang.isEmpty()) {
+        value += "@" + nx.getLanguage();
+        valueNb += "@" + nx.getLanguage();
       }
 
-      labelIterator = resource.listProperties(SKOS.altLabel);
-      //for each label
-      while (labelIterator.hasNext()) {
-        Literal nx = labelIterator.nextStatement().getLiteral();
-        String value = norm(nx.getLexicalForm());
-        String valueNb = normNb(nx.getLexicalForm());
-        String lang = nx.getLanguage();
-        if (lang != null && !lang.isEmpty()){
-          value += "@" + nx.getLanguage();
-          valueNb += "@" + nx.getLanguage();
-        }
-
-        // get the list or create a new one
-        List<Resource> ls = substitutionMap.computeIfAbsent(value, k -> new ArrayList<>());
-        List<Resource> lsNb = substitutionMapNoBrackets.computeIfAbsent(valueNb, k -> new ArrayList<>());
-        // add it to the list
-        ls.add(resource);
-        lsNb.add(resource);
+      // add the value or - if already there - keep the best one
+      putKeepBest(value, resource, substitutionMap);
+      putKeepBest(valueNb, resource, substitutionMapNoBrackets);
+    }
+
+    labelIterator = resource.listProperties(SKOS.altLabel);
+    //for each label
+    while (labelIterator.hasNext()) {
+      Literal nx = labelIterator.nextStatement().getLiteral();
+      String value = norm(nx.getLexicalForm());
+      String valueNb = normNb(nx.getLexicalForm());
+      // add the value or - if already there, skip
+      putOrSkip(value, resource, substitutionMapPlain);
+      putOrSkip(valueNb, resource, substitutionMapPlainNoBrackets);
+
+      String lang = nx.getLanguage();
+      if (lang != null && !lang.isEmpty()) {
+        value += "@" + nx.getLanguage();
+        valueNb += "@" + nx.getLanguage();
       }
+
+      // add the value or - if already there, skip
+      putOrSkip(value, resource, substitutionMap);
+      putOrSkip(valueNb, resource, substitutionMapNoBrackets);
     }
   }
 
+  private void putOrSkip(String value, Resource resource, Map<String, Resource> map) {
+    if (!map.containsKey(value))
+      map.put(value, resource);
+  }
+
+  private void putKeepBest(String value, Resource resource, Map<String, Resource> map) {
+    if (map.containsKey(value)) {
+      Resource oldRes = map.get(value);
+      Statement narrower = oldRes.getProperty(SKOS.narrower);
+      if (narrower != null) map.put(value, resource);
+    } else map.put(value, resource);
+  }
+
 
   @Override
   public Resource findConcept(String text, boolean strict, boolean excludeBrackets) {
-    String textOnly = text.replaceAll("@[a-z]{2,3}$", "");
-
-    Map<String, List<Resource>> map = excludeBrackets ? substitutionMapNoBrackets : substitutionMap;
-    for (Map.Entry<String, List<Resource>> entry : map.entrySet()) {
-      String key = entry.getKey();
-      String keyPlain = key.replaceAll("@[a-z]{2,3}$", "");
-
-      boolean textLangMatch = text.equalsIgnoreCase(key);
-      boolean textOnlyMatch = !strict && textOnly.equalsIgnoreCase(keyPlain);
-
-      if (textLangMatch || textOnlyMatch) {
-        List<Resource> matches = entry.getValue();
-        Resource bestMatch = null;
-        for (Resource m : matches) {
-          if (bestMatch == null) {
-            bestMatch = m;
-            continue;
-          }
-
-          // if I already had a "bestMatch"
-          // choose the most specific one (skos:narrower)
-          Statement narrower = bestMatch.getProperty(SKOS.narrower);
-          if (narrower != null) bestMatch = m;
-        }
-
-        return bestMatch;
-      }
-    }
-    return null;
+    // remove the lang tag if not strict
+    text = strict ? text : text.replaceAll("@[a-z]{2,3}$", "");
+
+    // select the right substitution map
+    Map<String, Resource> map;
+    if (strict)
+      map = excludeBrackets ? substitutionMapNoBrackets : substitutionMap;
+    else
+      map = excludeBrackets ? substitutionMapPlainNoBrackets : substitutionMapPlain;
+
+    return map.get(text.toLowerCase());
   }
 
 }