Perhaps you should try some spelling variations:
le literatura » la literatura, de literatura, e literatura
di filosofia » e filosofia
items studie » stems studies, cems studies, dems studies
items die » items der, items des

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 ((items studie) OR (items die)) ((di filosofia) OR (la filosofia)) le literatura.
• The words AND, OR and NOT may confuse the search; try adding quotes: "test ((items studie) or (items die)) ((di filosofia) OR (la filosofia)) le literatura".
• Adding a wildcard symbol may retrieve word variants: test ((items studie) or (items die)) ((di filosofia) OR (la filosofia)) le literatura*.