Perhaps you should try some spelling variations:
literature sarda » literature search, letteratura sarda, literature sacred
letteratura fra » letteratura da, letteratura greca, letteratura sarda
de letteratura » e letteratura, di letteratura, de litteratura
grund libro » gran libro, und libro
i grund » i ground, i grand
der a » der 2, der 1

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 grund libro de letteratura fra ) OR ( i grunde ((der a) OR (der _)) literature sarda ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( i grund libro de letteratura fra ) or ( i grunde ((der a) OR (der _)) literature sarda ))*".