Perhaps you should try some spelling variations:
di letteratura » de literatura, della letteratura
e letteratura » e literatur
i literatura » ii literatura, i literature, a literatura
y literatura » la literatura
grunde fir » grunde fur, grunde der, grunde die

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: (( i grunde fir ((e letteratura) OR (di letteratura)) sarda ) OR ( i grand livre ((i literatura) OR (y literatura)) de )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( i grunde fir ((e letteratura) or (di letteratura)) sarda ) or ( i grand livre ((i literatura) OR (y literatura)) de ))".
• Adding a wildcard symbol may retrieve word variants: (( i grunde fir ((e letteratura) or (di letteratura)) sarda ) or ( i grand livre ((i literatura) OR (y literatura)) de ))*.