<?xml version='1.0'?>
<patienten>
<patient>Mueller
   <arzt_id>1</arzt_id>
   <arzt_id>2</arzt_id>
   <arzt_id>3</arzt_id>
</patient>
<patient>Maier
   <arzt_id>2</arzt_id>
   <arzt_id>3</arzt_id>
</patient>
<patient>Meier
   <arzt_id>1</arzt_id>
   <arzt_id>2</arzt_id>
</patient>
<patient>Schulze
</patient>
</patienten>