Perhaps you should try some spelling variations:
en literatura » e literatura, pena literatura, en litterature
filosofia en » filosofia e, filosofia del, filosofia con
studium e » studium _, studium 3, studium 8
studium 1 » studium _, studium 3, studium 8

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 textos) duales ((studium e) OR (studium 1)) filosofia en literatura.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(texto or textos) duales ((studium e) OR (studium 1)) filosofia en literatura".
• Adding a wildcard symbol may retrieve word variants: (texto or textos) duales ((studium e) OR (studium 1)) filosofia en literatura*.