Perhaps you should try some spelling variations:
suitable studies » table studies, unstable studies, suitability studies
la litterature » a literature
la literatura » a literature
de filosofia » e filosofia, di filosofia, la filosofia
studies de » studies der, studies die, studies doe

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "most suitable studies de filosofia ((la literatura) OR (la litterature))".
• Adding a wildcard symbol may retrieve word variants: most suitable studies de filosofia ((la literatura) OR (la litterature))*.