Perhaps you should try some spelling variations:
forschungsberichte der » forschungsberichte des, forschungsbericht zum, erfahrungsberichte der
forschungsbericht 3 » forschungsbericht zum, forschungsberichte des, forschungsbereichen 4
3 lane » 3 land, 3 lake

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: "((\"((forschungsbericht 3) OR (forschungsberichte der)) landes nordrhein-westfalen\") or (\"forschungsbericht ((3 lane) OR (3 late)) nordrhein-westfalen\"))".
• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((\\"((forschungsbericht 3) OR (forschungsberichte der)) landes nordrhein-westfalen\\") or (\\"forschungsbericht ((3 lane) or (3 late)) nordrhein-westfalen\\"))\"".
• Removing quotes may allow a broader search: (( ((forschungsbericht 3) OR (forschungsberichte der)) landes nordrhein-westfalen ) or ( forschungsbericht ((3 lane) or (3 late)) nordrhein-westfalen )).