Perhaps you should try some spelling variations:
delle studien » duale studien, delphi studien, modell studien
5 filosofia » e filosofia, a filosofia, _ filosofia
y filosofia » e filosofia, a filosofia, la filosofia
tesi delle » testi delle, test delle, testi della

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: "tesi delle studien ((5 filosofia) OR (y filosofia)) a literature*".