Perhaps you should try some spelling variations:
duale studium » duales studium, dualen studium, das studium
di filosofia » la filosofia, e filosofia
tests duale » tests due, tests scale, tests damage
a filosofia » la filosofia, e filosofia

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: tests duale studium ((a filosofia) OR (di filosofia)) a literature.
• Adding a wildcard symbol may retrieve word variants: tests duale studium ((a filosofia) or (di filosofia)) a literature*.