diff --git a/mobile.netbiblio.php b/mobile.netbiblio.php
index 376b5a1..879ad67 100644
--- a/mobile.netbiblio.php
+++ b/mobile.netbiblio.php
@@ -225,18 +225,16 @@ class NetBiblio extends WebService
         return array_values(array_map(array($this, 'AddFiles'), $books));
     }
 
-    private function AddFiles(array $book)
+    private function GetFiles(array $ids)
     {
-        if(!isset($book['code'])) {
-             return $book;
-        }
+        $ids = array_map('intval', $ids);
 
         $uri = sprintf("%s%s",
             Configuration::get('checkfile_url'),
             http_build_query(array(
                 "client" => $this->client,
                 "login" => $this->login,
-                "book" => intval($book['code'])
+                "book" => implode(',', $ids),
             ))
         );
 
@@ -246,9 +244,15 @@ class NetBiblio extends WebService
         $json = curl_exec($ch);
         curl_close($ch);
 
-        $files = json_decode($json, true);
-        if (is_array($files)) {
-            $book['files'] = $files;
+        return json_decode($json, true);
+    }
+
+    private function AddFiles(array $book)
+    {
+        $files = $this->GetFiles(array($book['code']));
+
+        if (is_array($files) && isset($files[$book['code']])) {
+            $book['files'] = $files[$book['code']];
         } else {
             $book['files'] = array();
         }