<Author>
   <name>Collin Ruffenach</name>
   <age>23</age>
   <gender>mężczyzna</gender>
   <Books>
      <Book>
         <title>Objective-C dla programistów iPhone</title>
         <year>2010</year>
         <level>intermediate</level>
      </Book>
   </Books>
</Author>
