Perhaps you should try some spelling variations:
pela literatura » pena literatura, a literatura, de literatura
acute studien » acute studies, ante studien, aue studien
la literatura » la litterature, a literature
tests acute » testis acute, testing acute, versus acute
studien la » studien lap, studien a, studien l

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: tests acute studien la filosofia ((pela literatura) OR (la literatura)).
• Adding a wildcard symbol may retrieve word variants: tests acute studien la filosofia ((pela literatura) or (la literatura))*.