Perhaps you should try some spelling variations:
del literatura » de literatura, pela literatura, da literatura
orale studien » duale studien, frage studien, scale studien
ds filosofia » de filosofia, da filosofia, la filosofia
di filosofia » la filosofia, e filosofia
test orale » test oracle, test oral, test oracles

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 orale studien ((ds filosofia) OR (di filosofia)) del literatura".
• Adding a wildcard symbol may retrieve word variants: test orale studien ((ds filosofia) OR (di filosofia)) del literatura*.