Perhaps you should try some spelling variations:
"fehler allgemeiner" » "einer allgemeinen", "oder allgemeiner", "erster allgemeiner"
"felder allgemeine" » "feld allgemeine", "bildern allgemeine", "filter allgemeines"
"falle allgemeine" » "zelle allgemeine", "modelle allgemeine", "die allgemeine"

Try widening your search to All Fields.

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: (((("felder allgemeine") OR ("fehler allgemeiner"))) OR ("falle allgemeine")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"felder allgemeine\") OR (\"fehler allgemeiner\"))) or (\"falle allgemeine\"))".
• Removing quotes may allow a broader search: (((( felder allgemeine ) OR ( fehler allgemeiner ))) or ( falle allgemeine )).
• Adding a wildcard symbol may retrieve word variants: (((("felder allgemeine") OR ("fehler allgemeiner"))) or ("falle allgemeine"))*.