Perhaps you should try some spelling variations:
ban vanh » ban hanh, ban van, ban anh
vanh dai » van dai, vanh tai, lanh dao
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
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

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 ((nang xa) or (nang ma)) hoi. hieu ve pham duc ban vanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((nang xa) OR (nang ma)) hoi. hieu ve pham duc ban vanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sac ky ((nang xa) or (nang ma)) hoi. hieu ve pham duc ban vanh dai cua tre*.