Perhaps you should try some spelling variations:
duale studien » duale studium, scale studien, duales studium
de literatura » de litterature, la literatura, y literatura
de filosofia » e filosofia, di filosofia, la filosofia
filosofia de » filosofia del
studien de » studien der, studien die, studien des

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: "(testo OR tests) duale studien de filosofia de literatura*".