Perhaps you should try some spelling variations:
modell studien » model studies, models studies, moderne studien
filosofia da » filosofia de, filosofia e, filosofia della
test modell » tekst modell, test models, test model
studien am » studien a, studien aus, studien auf

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 modell studien am ((filosofia da) OR (filosofia del)) literatura".
• Adding a wildcard symbol may retrieve word variants: test modell studien am ((filosofia da) OR (filosofia del)) literatura*.