Perhaps you should try some spelling variations:
orale studien » duale studien, frage studien, globale studien
scale studien » scale studies, scale student, duale studien
der filosofia » de filosofia, e filosofia, di filosofia
filosofia a » filosofia da, filosofia la, filosofia e

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "test ((orale studien) OR (scale studien)) der filosofia a literature*".