Perhaps you should try some spelling variations:
la literatura » la litterature, a literature
filosofia la » filosofia da, filosofia le, filosofica da
tests scale » tests stable, sets scale, tests safe
studien das » studie das, studien des, studien der
studien 4 » studien _, studien 3, studien 5

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: "tests scale ((studien das) OR (studien 4)) filosofia la literatura*".