diff --git a/Lib/Search/BookSearch.php b/Lib/Search/BookSearch.php
index 55b5756..241b66f 100644
--- a/Lib/Search/BookSearch.php
+++ b/Lib/Search/BookSearch.php
@@ -125,6 +125,8 @@ class BookSearch
 
         $bs = new static();
         $bs->addOrQuery($codes, $field);
+        $bs->addSortField('author', \SolrQuery::ORDER_ASC);
+        $bs->addSortField('title', \SolrQuery::ORDER_ASC);
         $results = $bs->getResults(0, $count);
         return $results['books'];
     }