Perhaps you should try some spelling variations:
de litterature » la litterature, et litterature
case studies » case study
de filologia » di filologia, de filosofia, e fisiologia
e filologia » di filologia, e fisiologia, e filosofia
rats case » rates case, raths case, rats causes

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: "rats case studies ((e filologia) OR (de filologia)) de litterature".
• Adding a wildcard symbol may retrieve word variants: rats case studies ((e filologia) OR (de filologia)) de litterature*.