Perhaps you should try some spelling variations:
de literatura » de litterature, la literatura, y literatura
duale studium » duales studium, dualen studium, das studium
es filosofia » em filosofia, la filosofia, di filosofia
e filosofia » la filosofia
testo » test, tests, texto

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: testo duale studium ((es filosofia) OR (e filosofia)) de literatura*.