Perhaps you should try some spelling variations:
le literatura » la literatura, de literatura, e literatura
filosofia le » filosofia de, filosofia e, filosofia del
test modell » tekst modell, test models, test model
studien auf » studien aus, studie auf
studien am » studien a, studien aus, studien _

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