Update Source.php

Author: kasparsj

src/Scopus/Response/Source.php

@@ -14,7 +14,8 @@ public function __construct(array $data)
 
     public function getTitle()
     {
-        return isset($this->data['sourcetitle']) ? $this->data['sourcetitle'] : null;
+        $sourcetitle = isset($this->data['sourcetitle']) ? $this->data['sourcetitle'] : null;
+        return is_array($sourcetitle) ? $sourcetitle['$'] : $sourcetitle;
     }
 
     public function getTitleAbbrev()
@@ -62,4 +63,4 @@ public function getVolume()
         $volIss = $this->getVoliss();
         return $volIss && isset($volIss['@volume']) ? $volIss['@volume'] : null;
     }
-}
+}