Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
qua hoc » cua hoc, quang hoc, qua hoat
dao hai » dao thai, dai hai, do hai
hai cua » thai cua, dai cua, hoi cua
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 qua hoc nuoc va dao hai 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 qua hoc nuoc va dao hai cua te.
• Adding a wildcard symbol may retrieve word variants: tu sach ((y lang) or (o lang)) xa hoi. hieu qua hoc nuoc va dao hai cua te*.