Perhaps you should try some spelling variations:
stadler studien » realer studien, stifter studien, studie studien
tests stadler » tests stable, 21st stadler, teste stadien
der filosofia » de filosofia, e filosofia, di filosofia
de literatura » de litterature, y literatura, a literatura
la literatura » la litterature, a literature
studien der » studie der, studenten der

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