Perhaps you should try some spelling variations:
da literatura » la literatura, a literatura, de literatura
de filosofia » e filosofia, di filosofia, la filosofia
studium de » studium der, studium des, studium die
testo das » test das, tests das, testen das

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 das studium de filosofia ((da literatura) OR (a literature))*.