Perhaps you should try some spelling variations:
hieu cua » hieu qua, dieu cua, bieu cua
tu sach » thu sach, su sach, te sach
cua hoc » cua hoi, cua thuoc, cua nuoc
dao lai » dao lam, dao bai, dao hai
lai cua » dai cua, hai cua, lai chau
y lang » _ lang, tay lang, yen lang
o lang » hoa lang, hoi lang
va dao » ca dao
cua te » cua tu
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) or (o lang)) xa hoi. hieu cua hoc nuoc va dao lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y lang) OR (o lang)) xa hoi. hieu cua hoc nuoc va dao lai cua te.
• Adding a wildcard symbol may retrieve word variants: tu sach ((y lang) or (o lang)) xa hoi. hieu cua hoc nuoc va dao lai cua te*.