Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh hai » thanh phan, thanh hoa, thanh san
dau luan » dan luan, dat luan, khau luan
luan ban » luan van, luan san, luan han
nang xa » nang x, nang ma, mang xa
hai cua » thai cua, dai cua, hoi cua
lang xa » lang ha, dang xay, lang van
hieu va » hieu qua
su sac » su sach, su cac, su xac
cua te » cua tu
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 (lang xa)) hoi. ((hieu va) or (lieu va)) dau luan ban thanh hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((nang xa) OR (lang xa)) hoi. ((hieu va) OR (lieu va)) dau luan ban thanh hai cua te.
• Adding a wildcard symbol may retrieve word variants: su sac ky ((nang xa) or (lang xa)) hoi. ((hieu va) or (lieu va)) dau luan ban thanh hai cua te*.