Perhaps you should try some spelling variations:
le letterature » e letterature, la litterature, e letteratura
das filosofia » da filosofia, la filosofia, di filosofia
dello studio » nello studio, allo studio, dello stato
filosofia le » filosofia de, filosofia e, filosofia del
dem studium » das studium, im studium, zum 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: testi ((dello studio) OR (dem studium)) das filosofia le letterature.
• Adding a wildcard symbol may retrieve word variants: testi ((dello studio) or (dem studium)) das filosofia le letterature*.