Perhaps you should try some spelling variations:
hieu hieu » hien hieu, hieu hien, thien hieu
hieu cac » hieu luc, hieu va, hieu van
danh vai » danh sai, danh va, doanh van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho
bo va » bao va, so va, co va
do va » do van, so va

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 ky nang x hoi. hieu hieu cac ((bo va) or (do va)) danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu hieu cac ((bo va) OR (do va)) danh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu hieu cac ((bo va) or (do va)) danh vai cua tre*.