$book->addChapter('Title', 'Title.html', $titlepage, true, EPub::EXTERNAL_REF_ADD);
$chapter = $content_start . $entry->getContent() . $bookEnd;
$book->addChapter($entry->getTitle(), htmlspecialchars($filename) . '.html', $chapter, true, EPub::EXTERNAL_REF_ADD);
$book->addChapter('Title', 'Title.html', $titlepage, true, EPub::EXTERNAL_REF_ADD);
$chapter = $content_start . $entry->getContent() . $bookEnd;
$book->addChapter($entry->getTitle(), htmlspecialchars($filename) . '.html', $chapter, true, EPub::EXTERNAL_REF_ADD);