Perhaps you should try some spelling variations:
de litterature » et litterature
la litterature » a literature
die filologia » di filologia, de filologia, e filologia
studies die » studie die, studien die, studies does
rats » rat

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: ((rats OR rate) OR rays) gavage studies die filologia ((de litterature) OR (la litterature)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((rats or rate) or rays) gavage studies die filologia ((de litterature) OR (la litterature))".
• Adding a wildcard symbol may retrieve word variants: ((rats or rate) or rays) gavage studies die filologia ((de litterature) OR (la litterature))*.