Perhaps you should try some spelling variations:
en litterature » et litterature, une litterature, la litterature
di filosofia » la filosofia, e filosofia
da filosofia » la filosofia, a filosofia, de filosofia
des studium » des studiums, das studium, dem studium
test des » test der, test test

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: test des studium ((da filosofia) OR (di filosofia)) en litterature.
• Adding a wildcard symbol may retrieve word variants: test des studium ((da filosofia) or (di filosofia)) en litterature*.