Perhaps you should try some spelling variations:
ban hanh » ban hang
hanh dai » hanh tai, hanh dao, vanh dai
nang xa » nang x, lang xa, nang ma
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 (mang may)) hoi. hieu ve pham duc ban hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((nang xa) OR (mang may)) hoi. hieu ve pham duc ban hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sac ky ((nang xa) or (mang may)) hoi. hieu ve pham duc ban hanh dai cua tre*.