Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
nang ma » tang ma, sang ma, nang cao
hieu vi » hieu voi, hieu va, hieu ve
va hanh » van hanh, va thanh, va danh
tu can » tu ban, tu cac, thu canh
can ky » van ky, dan ky, ban ky
cuc te » cua te, cuc thue, cuc tieu
pham » phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can ky ((nang ma) or (nang x)) hoi. hieu vi pham duc va hanh tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky ((nang ma) OR (nang x)) hoi. hieu vi pham duc va hanh tai cuc te.
• Adding a wildcard symbol may retrieve word variants: tu can ky ((nang ma) or (nang x)) hoi. hieu vi pham duc va hanh tai cuc te*.