Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh van » thanh san, thanh toan, thanh phan
hieu van » thien van, lieu va, hieu ve
cuu tre » cua tre, cau tren, cau treo
lam duc » lam duoc, pham duc, nam duoc
nang xa » nang x, lang xa, mang xa
van cuu » van cau, van chu, van cu
nang ma » tang ma, sang ma, nang cao
duc ban » duc tan, duc van, dua ban
hieu va » lieu va, hieu qua
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 van) OR (hieu va)) lam duc ban thanh van cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((nang xa) OR (nang ma)) hoi. ((hieu van) OR (hieu va)) lam duc ban thanh van cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky ((nang xa) or (nang ma)) hoi. ((hieu van) OR (hieu va)) lam duc ban thanh van cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sac ky ((nang xa) or (nang ma)) hoi. ((hieu van) OR (hieu va)) lam duc ban thanh van cuu tre*.