Perhaps you should try some spelling variations:
del literatur » model literatur, teil literatur, igel literatur
studium la » studium a, studium als, studium das
test das » test day, west das, testen das
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 das) OR (test des)) studium la filosofia del literatur".
• Adding a wildcard symbol may retrieve word variants: ((test das) OR (test des)) studium la filosofia del literatur*.