Perhaps you should try some spelling variations:
le letterature » e letterature, la litterature, e letteratura
di filosofia » la filosofia, e filosofia
des studium » des studiums, das studium, dem studium
a filosofia » la filosofia, e filosofia
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 ((di filosofia) OR (a filosofia)) le letterature.
• Adding a wildcard symbol may retrieve word variants: test des studium ((di filosofia) or (a filosofia)) le letterature*.