Perhaps you should try some spelling variations:
de literatura » de litterature, la literatura, y literatura
filosofico de » filosoficos de, filosofico e, filosofico di
e filosofico » e filosofica, y filosofico, e filosofiche
1 studies » 2 studies, 4 studies, 3 studies
1 studie » 1 studien, 3 studie, 11 studies

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: test ((1 studie) OR (1 studies)) e filosofico de literatura.
• Adding a wildcard symbol may retrieve word variants: test ((1 studie) or (1 studies)) e filosofico de literatura*.