Perhaps you should try some spelling variations:
duales studium » das studium
en literatura » e literatura, pena literatura, en litterature
a filosofia » la filosofia, di filosofia
e filosofia » la filosofia

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: (texto OR texts) duales studium ((a filosofia) OR (e filosofia)) en literatura.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(texto or texts) duales studium ((a filosofia) OR (e filosofia)) en literatura".
• Adding a wildcard symbol may retrieve word variants: (texto or texts) duales studium ((a filosofia) OR (e filosofia)) en literatura*.