Perhaps you should try some spelling variations:
christoph tresch » christoph trebesch, christoph rausch, christoph irmscher
christoph rasche » christoph fischer, christoph reich, christoph erath
christoph buch » christoph buck, christoph ich, christoph bruns

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: johann ((christoph buch) OR (((christoph tresch) OR (christoph rasche)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "johann ((christoph buch) or (((christoph tresch) OR (christoph rasche))))".
• Adding a wildcard symbol may retrieve word variants: johann ((christoph buch) or (((christoph tresch) OR (christoph rasche))))*.