Perhaps you should try some spelling variations:
a litterature » la litterature, _ litterature, et litterature
da filosofia » la filosofia, di filosofia, a filosofia
der studium » oder studium, dem studium, des studium
d filosofia » di filosofia, de filosofia, e filosofia
test » text

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: test der studium ((d filosofia) OR (da filosofia)) ((a litterature) OR (a literature)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "test der studium ((d filosofia) OR (da filosofia)) ((a litterature) or (a literature))".
• Adding a wildcard symbol may retrieve word variants: test der studium ((d filosofia) OR (da filosofia)) ((a litterature) or (a literature))*.