Perhaps you should try some spelling variations:
"fehler allgemeiner" » "lehrers allgemeiner", "einer allgemeinen", "oder allgemeiner"
"felder allgemeine" » "feld allgemeine", "bildern allgemeine", "filter allgemeines"
"deren allgemeine" » "denken allgemeine", "energien allgemeine", "tumoren allgemeine"

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: (((("deren allgemeine") OR ("felder allgemeine"))) OR ("fehler allgemeiner")).
• Removing quotes may allow a broader search: (((( deren allgemeine ) or ( felder allgemeine ))) or ( fehler allgemeiner )).
• Adding a wildcard symbol may retrieve word variants: (((("deren allgemeine") or ("felder allgemeine"))) or ("fehler allgemeiner"))*.