Perhaps you should try some spelling variations:
hieu suat » hieu luat, hieu qua
hieu sau » hieu su, tieu su, hieu va
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
sang ky » sang kyo, dang ky, tang ky
tu sang » thu sang, tu san, tu lang
lai hoi » dai hoi, lai hoa, mai hoi
lai roi » loi roi
ky sang » ky nang, ky dang, ky tang
vi cua » vai cua, di cua
cua te » cua tu
xu va » xu van, tu va, su va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sang ky sang ((lai hoi) or (lai roi)). ((hieu sau) OR (hieu suat)) chao xu va danh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sang ky sang ((lai hoi) OR (lai roi)). ((hieu sau) OR (hieu suat)) chao xu va danh vi cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sang ky sang ((lai hoi) or (lai roi)). ((hieu sau) OR (hieu suat)) chao xu va danh vi cua te*".