Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
cua tre » cua te, cuu tre, cua triet
cac duc » cac du, cac dac, cac nuoc
tai cua » thai cua, tai cuc, tri cua
cao duc » dao duc, cao suc, giao duc
hieu ve » hieu va, hieu van
tu sac » tu sach, tu cac, tu bac
nang o » nang co, nang ho, nang ro
tu san » thu san, tu ban, tu can
o lai » o lao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sac) or (tu san)) ky nang o lai. hieu ve ((cac duc) or (cao duc)) van hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu san)) ky nang o lai. hieu ve ((cac duc) OR (cao duc)) van hanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu san)) ky nang o lai. hieu ve ((cac duc) or (cao duc)) van hanh tai cua tre*.