diff -r 04e728651a48 -r 0a2c2ad49d75 server/src/app/Http/Controllers/Api/DocumentController.php
--- a/server/src/app/Http/Controllers/Api/DocumentController.php	Thu Oct 13 13:01:12 2016 +0200
+++ b/server/src/app/Http/Controllers/Api/DocumentController.php	Fri Oct 14 01:02:10 2016 +0200
@@ -9,6 +9,7 @@
 use CorpusParole\Http\Controllers\Controller;
 use CorpusParole\Repositories\DocumentRepository;
 use CorpusParole\Services\TranscriptManager;
+use CorpusParole\Libraries\Filters\CorpusFilterManager;
 
 class DocumentController extends Controller
 {
@@ -32,7 +33,7 @@
         $filters = [];
         $languages = $request->input('language', []);
         if(!empty($languages)) {
-            $filters['language'] = $languages;
+            $filters['language'] = CorpusFilterManager::prepareLanguages($languages);
         }
         $sort = $request->input('sort', null);