Perhaps you should try some spelling variations:
duale studien » duale studium, scale studien, duales studium
le literatura » de literatura, e literatura, de litteratura
la literatura » la litterature, a literature
test duale » test double, test delle, test orale

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 duale studien _ filosofia ((le literatura) OR (la literatura))".
• Adding a wildcard symbol may retrieve word variants: test duale studien _ filosofia ((le literatura) OR (la literatura))*.