Perhaps you should try some spelling variations:
de litterature » la litterature, et litterature
duale studium » duales studium, dualen studium, das studium
dd filosofia » de filosofia, da filosofia, la filosofia
di filosofia » la filosofia, e filosofia
test duale » test double, test delle, test orale

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: "test duale studium ((dd filosofia) OR (di filosofia)) de litterature".
• Adding a wildcard symbol may retrieve word variants: test duale studium ((dd filosofia) OR (di filosofia)) de litterature*.