/**
  * Add links for author, subject, related titles
  * 
  * @param Record $xerxes_record
  */
 public function addBibRecordLinks(Record $xerxes_record)
 {
     // author links
     foreach ($xerxes_record->getAuthors() as $author) {
         $author->url = $this->linkAuthor($author);
         $author->url_title = $this->linkAuthorTitle($author);
     }
     // subject links
     foreach ($xerxes_record->getSubjects() as $subject) {
         $subject->url = $this->linkSubject($subject);
     }
     // related titles link
     foreach ($xerxes_record->getPrecedingTitles() as $title) {
         $title->url = $this->linkRelatedTitle($title);
     }
 }