Perhaps you should try some spelling variations:
stable studien » stadler studien, table studies, unstable studies
die filosofica » di filosofia, de filosofia, e filosofica
scale studien » scale studies, scale student, duale studien
filosofica a » filosofica da, filosofica e, filosofica _
a literatura » la literatura, a literature, y literatura

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 ((stable studien) OR (scale studien)) die filosofica a literatura*".