diff --git a/Lib/Search/BookSearch.php b/Lib/Search/BookSearch.php
index 5117e5c..f161965 100644
--- a/Lib/Search/BookSearch.php
+++ b/Lib/Search/BookSearch.php
@@ -76,7 +76,7 @@ class BookSearch
             throw new WebException ("SolrError", $e->getMessage(), -700);
         }
 
-        $books = isset($results['response']['docs']) ?
+        $books = isset($results['response']['docs']) && $results['response']['docs'] ?
             array_map(function($o) { return (array) $o; }, $results['response']['docs']) :
             false;
 
diff --git a/NetBiblio.php b/NetBiblio.php
index 2554e4c..d2c7268 100644
--- a/NetBiblio.php
+++ b/NetBiblio.php
@@ -214,12 +214,12 @@ class NetBiblio extends WebService
 
     public function FindBooks($codes)
     {
-        $this->CheckSession();
+        $codes = json_decode($codes);
+        $bs = new BookSearch();
+        $bs->addQuery('code:('.implode(' OR ', $codes).')', null, false);
+        $results = $bs->getResults(0, count($codes));
+        return $results['books'] ? $this->AddBookData($results['books']) : array();
 
-        $codes = json_decode($codes, true);
-        $codes = array_map('intval', $codes);
-        $books = AudioBook::findBy('NoticeNr', $codes, true);
-        return array_values($this->AddBookData($books));
     }
 
     private function GetFiles(array $ids)
@@ -364,11 +364,10 @@ class NetBiblio extends WebService
 
     public function FindBook($code)
     {
-        $this->CheckSession();
-
-        $code = intval($code);
-        $book = AudioBook::findBy('NoticeNr', $code, true);
-        return $this->AddBookData($book);
+        $bs = new BookSearch();
+        $bs->addQuery($code, 'code');
+        $results = $bs->getResults(0, 1);
+        return $results['books'] ? reset($this->AddBookData($results['books'])) : null;
     }
 
     public function GetRandomBooks($number = 100, $seed = null) {