Perhaps you should try some spelling variations:
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
dao dai » dat dai, dao dan, tao dai
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land
va hoc » van hoc
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: su sach ((y lang) or (_ lang)) xa hoi. hieu va hoc nuoc va dao dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y lang) OR (_ lang)) xa hoi. hieu va hoc nuoc va dao dai cua te.
• Adding a wildcard symbol may retrieve word variants: su sach ((y lang) or (_ lang)) xa hoi. hieu va hoc nuoc va dao dai cua te*.