diff --git a/mobile.netbiblio.php b/mobile.netbiblio.php
index 3c96d8f..604fd0c 100644
--- a/mobile.netbiblio.php
+++ b/mobile.netbiblio.php
@@ -254,9 +254,47 @@ class NetBiblio extends WebService
             return reset($result);
         }
 
-        $ids = array_map(function($b) { return $b['code']; }, $books);
+        // add complementary data to each book
+        $books = array_map(function($b) {
+            // add files if we already have them
+            $files = array();
+            $samples = array();
+            foreach(array('mp3', 'ogg') as $ext) {
+                $k = 'sample_'.$ext;
+                if(isset($b[$k]) && strlen($b[$k]) > 0) {
+                    $samples[] = $b[$k];
+                }
+                unset($b[$k]);
+            }
+            if(! empty($samples)) {
+                $files['samples'] = $samples;
+            }
+            if(isset($b['zip']) && strlen($b['zip']) > 0) {
+                $files['zip'] = $b['zip'];
+                unset($b['zip']);
+            }
+
+            if(! empty($files)) {
+                $b['files'] = $files;
+            }
+
+            // add date if we have an availabilityDate for Mobile apps compatibility
+            if(! isset($b['date']) && isset($b['availabilityDate'])) {
+                $b['date'] = date('Y.m.d', strtotime($b['availabilityDate']));
+            }
+
+            return $b;
+        }, $books);
+
+        // retrieve files information for the book that don't have any at this time
+        $booksWithoutFiles = array_filter($books, function($b) {
+            return ! isset($b['files']);
+        });
+
+        $ids = array_map(function($b) { return $b['code']; }, $booksWithoutFiles);
         $files = $this->GetFiles($ids);
-        foreach($books as $k => $b) {
+
+        foreach($booksWithoutFiles as $k => $b) {
             if(isset($files[$b['code']])) {
                 $books[$k]['files'] = $files[$b['code']];
             } else {