diff --git a/src/Entity/AudioTalkBook.php b/src/Entity/AudioTalkBook.php
new file mode 100644
index 0000000..f3b561e
--- /dev/null
+++ b/src/Entity/AudioTalkBook.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Bookboon\Api\Entity;
+
+class AudioTalkBook extends Book
+{
+    const _OWN_TYPE = Book::TYPE_AUDIOTALK;
+}
diff --git a/src/Entity/Book.php b/src/Entity/Book.php
index c79a76b..17be9ef 100644
--- a/src/Entity/Book.php
+++ b/src/Entity/Book.php
@@ -7,13 +7,14 @@
 use Bookboon\Api\Client\ClientInterface;
 use Bookboon\Api\Exception\UsageException;
 
-class Book extends Entity
+abstract class Book extends Entity
 {
     const _OWN_TYPE = '';
 
     const TYPE_AUDIO = 'audio';
     const TYPE_PDF = 'pdf';
     const TYPE_VIDEO = 'video';
+    const TYPE_AUDIOTALK = 'audioTalk';
 
     const FORMAT_PDF = 'pdf';
     const FORMAT_EPUB = 'epub';
@@ -111,7 +112,7 @@ public static function getAll(
      * @param array $objectArray
      * @return Book
      */
-    private static function objectTransformer(array $objectArray)
+    public static function objectTransformer(array $objectArray)
     {
         $className = 'Bookboon\Api\Entity\\' . ucfirst($objectArray['_type']) . 'Book';
         return new $className($objectArray);
@@ -125,7 +126,13 @@ public static function getEntitiesFromArray(array $array)
     {
         $entities = [];
         foreach ($array as $object) {
-            $entities[] = self::objectTransformer($object);
+            if (in_array(
+                $object['_type'],
+                [self::TYPE_PDF, self::TYPE_AUDIO, self::TYPE_VIDEO, self::TYPE_AUDIOTALK],
+                true)
+            ) {
+                $entities[] = self::objectTransformer($object);
+            }
         }
 
         return $entities;
diff --git a/src/Entity/Exam.php b/src/Entity/Exam.php
index 2080450..fafdbb2 100644
--- a/src/Entity/Exam.php
+++ b/src/Entity/Exam.php
@@ -128,11 +128,10 @@ public function getTimeSeconds()
      * Return book to which the exam is related
      *
      * @return Book
-     * @throws \Bookboon\Api\Exception\EntityDataException
      */
     public function getBook()
     {
-        return new Book($this->safeGet('book', []));
+        return Book::objectTransformer($this->safeGet('book', []));
     }
 
     /**
diff --git a/tests/Entity/BookTest.php b/tests/Entity/BookTest.php
index dc3d92f..45ff6b0 100644
--- a/tests/Entity/BookTest.php
+++ b/tests/Entity/BookTest.php
@@ -107,7 +107,7 @@ public function testHasPdf()
      */
     public function testInvalidBook()
     {
-        $book = new Book(['blah']);
+        $book = new PdfBook(['blah']);
     }
 
     public function testBookDownloadOauth()