diff -r 4fca650b9b8a -r fac22d8c2df8 server/src/app/Libraries/Utils.php
--- a/server/src/app/Libraries/Utils.php	Tue Feb 23 18:52:27 2016 +0100
+++ b/server/src/app/Libraries/Utils.php	Thu Feb 25 10:20:01 2016 +0100
@@ -1,6 +1,9 @@
 <?php
 namespace CorpusParole\Libraries;
 
+use EasyRdf\Literal;
+use EasyRdf\Resource;
+
 /**
  * Utilities functions
  */
@@ -90,15 +93,20 @@
         return $mime_types[$extension];
     }
 
-    public static function processLiteralOrString($val) {
+    public static function processLiteralResourceOrString($val) {
         if(is_null($val)) {
             return $val;
         }
         if($val instanceof Literal) {
             return $val->getValue();
         }
+        elseif ($val instanceof Resource) {
+            return $val->getUri();
+        }
         else {
             return (string)$val;
         }
     }
+
+
 }