Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
qua cac » cua cac
cac tuc » cac toc, cac tu, cac tac
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land
tuc va » thuc va, truc va, tuc xa
va dao » ca dao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((y lang) OR (_ lang)) xa hoi. hieu qua cac tuc va dao ((vai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y lang) OR (_ lang)) xa hoi. hieu qua cac tuc va dao ((vai cua) OR (hai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y lang) OR (_ lang)) xa hoi. hieu qua cac tuc va dao ((vai cua) or (hai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y lang) OR (_ lang)) xa hoi. hieu qua cac tuc va dao ((vai cua) or (hai cua)) tre*.