Outlook 2003 Calendar entries owner

We have more than 10 calendars (meeting rooms) shared out to Admin clerks with Author Permission.

Sometimes, the Admin clerks would request to know who had booked a particular room and I’m scratching my heads all round to find an answer.

Tried using System Manager, AD but still could not find who had booked the rooms unless I delete the entries and tried using Recover Delete Items then I could see who booked the rooms.

Any idea?

Thanks.