Perhaps you should try some spelling variations:
la literatura » la litterature, a literature
duale studien » duale studium, scale studien, duales studium
ds 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 studien ((ds filosofia) OR (di filosofia)) la literatura".
• Adding a wildcard symbol may retrieve word variants: test duale studien ((ds filosofia) OR (di filosofia)) la literatura*.