Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh dai » thanh hai, thanh tai, thanh dat
ky tang » ky nang, ky dang, kho tang
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
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ma hoi » mai hoi, ma hoa, me hoi
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky tang ((ma hoi) or (xa hoi)). hieu ve cac duc ban thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky tang ((ma hoi) OR (xa hoi)). hieu ve cac duc ban thanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sac ky tang ((ma hoi) or (xa hoi)). hieu ve cac duc ban thanh dai cua tre*.