Perhaps you should try some spelling variations:
con literatura » omni literatura, pena literatura, la literatura
drug studium » drug studies, drugs studies, beruf studium
a filosofia » la filosofia, di filosofia
e filosofia » la filosofia
tests drug » test drug, testing drug, tests during

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "tests drug studium ((a filosofia) OR (e filosofia)) con literatura".
• Adding a wildcard symbol may retrieve word variants: tests drug studium ((a filosofia) OR (e filosofia)) con literatura*.