Perhaps you should try some spelling variations:
letteratura sarda » letteratura storia, letteratura sulla, letteratura arte
de letteratura » e letteratura, di letteratura, de litterature
de litteratura » de litterature, de literatura, e letteratura
la letteratura » la litterature, la literatura, e letteratura
grundlage der » grundlagen der
grund libro » gran libro, und libro
grunde die » grunde des, grundlage die, grundung die
grunde der » grund der, grundzuge der
i grund » i grunde, i ground, i grand

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) OR (de litteratura)) fra ) OR ( i ((grunde die) OR (((grunde der) OR (grundlage der)))) la letteratura sarda )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( i grund libro ((de letteratura) or (de litteratura)) fra ) or ( i ((grunde die) or (((grunde der) OR (grundlage der)))) la letteratura sarda ))".
• Adding a wildcard symbol may retrieve word variants: (( i grund libro ((de letteratura) or (de litteratura)) fra ) or ( i ((grunde die) or (((grunde der) OR (grundlage der)))) la letteratura sarda ))*.