Perhaps you should try some spelling variations:
delle studien » duale studien, delphi studien, modell studien
e literature » e literatur, life literature, prose literature
testi delle » tesi delle, test delle, testi della
a filosofia » e filosofia, di filosofia

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: "testi delle studien ((a filosofia) OR (la filosofia)) e literature*".