Perhaps you should try some spelling variations:
suitable studies » table studies, unstable studies, suitability studies
de filosofica » de filosofia, e filosofia, di filosofia
e filosofica » e filosofia, e filosofiche, a filosofia
a literatura » la literatura, a literature, y literatura

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 filosofica) OR (e filosofica)) a literatura".
• Adding a wildcard symbol may retrieve word variants: most suitable studies ((de filosofica) OR (e filosofica)) a literatura*.