Perhaps you should try some spelling variations:
zur islamforschung » zur dialogforschung, zur raumforschung, zur feldforschung
segner beitrage » seiner beitrage, essener beitrage, neuer beitrage
essen beitrage » essener beitrage, wissen beitrage, wissens beitrage

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: ((essen beitrage) OR (segner beitrage)) zur islamforschung.
• Adding a wildcard symbol may retrieve word variants: ((essen beitrage) or (segner beitrage)) zur islamforschung*.