Perhaps you should try some spelling variations:
duale studien » duale studium, scale studien, duales studium
der filosofia » de filosofia, e filosofia, di filosofia
de literatura » de litterature, la literatura, a literatura
y literatura » la literatura
tests duale » tests due, tests scale, tests damage
studien der » studie der, studenten der

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 duale studien der filosofia ((de literatura) OR (y literatura))".
• Adding a wildcard symbol may retrieve word variants: tests duale studien der filosofia ((de literatura) OR (y literatura))*.