Perhaps you should try some spelling variations:
ban hanh » ban hang
hanh tri » thanh tri, hanh tai, hanh trinh
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
tu sac » tu sach, tu cac, tu san
tu ban » thu ban, te ban
nang o » nang co, nang ho, nang ro
ve cac » va cac, vien cac
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 ban)) ky nang o lai. hieu ve cac duc ban hanh tri cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu ban)) ky nang o lai. hieu ve cac duc ban hanh tri cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu ban)) ky nang o lai. hieu ve cac duc ban hanh tri cua tre*.