Perhaps you should try some spelling variations:
a litterature » la litterature, a literature, _ litterature
filosofia a » filosofia da, filosofia la, filosofia e
studium am » studium im, studium als, studium das
studium a » studium ad, studium _, studium 1
test des » test der, test test

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 des ((studium a) OR (studium am)) filosofia a litterature".
• Adding a wildcard symbol may retrieve word variants: test des ((studium a) OR (studium am)) filosofia a litterature*.