Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
hieu va » lieu va
lai cua » dai cua, lai chau, thai cua
hai cua » thai cua, dai cua, hoi cua
y lang » o lang, _ lang, tay lang
va dao » ca dao
nuoc » quoc, duoc, ngoc

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