Perhaps you should try some spelling variations:
suitable studies » table studies, unstable studies, suitability studies
de literatura » de litterature, y literatura, a literatura
la literatura » la litterature, 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 ((de literatura) OR (la literatura))".
• Adding a wildcard symbol may retrieve word variants: most suitable studies de filosofia ((de literatura) OR (la literatura))*.