Perhaps you should try some spelling variations:
na literatura » la literatura, a literatura, y literatura
di filosofia » la filosofia, e filosofia
des studium » des studiums, das studium, dem studium
studium di » studium die, studium i, studium ii
text des » text der

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: "text des studium di filosofia ((na literatura) OR (a literature))*".