Perhaps you should try some spelling variations:
hieu suat » hieu luat, hieu qua
hieu sau » hieu su, tieu su, hieu va
sang lai » sang tai, sang lap, mang lai
van hanh » van thanh, ban hanh, van anh
tu sang » thu sang, tu lang, tu quang
lai hoi » dai hoi, lai hoa, lai roi
ky sang » ky nang, ky dang, ky tang
tu san » thu san, tu ban, tu can
xu van » tu van, vu van, su van
vi cua » vai cua, di cua
cua te » cua tu

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) or (tu san)) ky sang lai hoi. ((hieu sau) OR (hieu suat)) chao xu van hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sang) OR (tu san)) ky sang lai hoi. ((hieu sau) OR (hieu suat)) chao xu van hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sang) or (tu san)) ky sang lai hoi. ((hieu sau) OR (hieu suat)) chao xu van hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sang) or (tu san)) ky sang lai hoi. ((hieu sau) OR (hieu suat)) chao xu van hanh vi cua te*.