Perhaps you should try some spelling variations:
zur feldforschung » der feldforschung, zur trendforschung, zur erforschung
essener beitrage » essen beitrage, eigenes beitrage, segner beitrage
beitrage zur » beitrag zur

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

• Adding a wildcard symbol may retrieve word variants: essener beitrage zur feldforschung*.