Perhaps you should try some spelling variations:
suitable studie » suitable source
la litterature » a literature
test suitable » best suitable, most suitable, notes suitable
la literatura » a literature
y filosofia » e filosofia, a filosofia, la filosofia
studie y » studie 2, studie _, studie 1

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: "test suitable studie y filosofia ((la literatura) OR (la litterature))*".