Perhaps you should try some spelling variations:
de litterature » la litterature, et litterature
test studium » test studies, selbst studium, das studium
di filosofia » la filosofia, e filosofia
filosofia de » filosofia del
des studium » des studiums, das studium, dem studium

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