Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
lam duoc » nam duoc, luat duoc, lam thuoc
cuu tre » cua tre, cau tren, cau treo
san cuu » san cua, san huu, song cuu
lam duc » pham duc, nam duoc, lam dung
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
sac ky » cac ky, sai ky
su sac » su sach, su cac, su xac

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 ((lam duc) OR (lam duoc)) ban thanh san 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 ((lam duc) OR (lam duoc)) ban thanh san 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 ((lam duc) OR (lam duoc)) ban thanh san cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sac ky ((nang xa) or (nang ma)) hoi. hieu van ((lam duc) OR (lam duoc)) ban thanh san cuu tre*.