Perhaps you should try some spelling variations:
va hanh » van hanh, va thanh, ban hanh
mang xa » lang xa, mang may, dang xay
hoi cua » hoi chuc
nang ma » tang ma, sang ma, nang cao
va danh » va dinh, va dan, dia danh
hieu va » lieu va, hieu qua
cao luc » bao luc, cao duc, cao suc
tu sai » tu bai, tu san, tu cai
va cao » va cac, va co, va dao
sai ky » sac ky
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky ((mang xa) or (nang ma)) hoi. hieu va cao luc ((va hanh) or (va danh)) hoi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky ((mang xa) OR (nang ma)) hoi. hieu va cao luc ((va hanh) OR (va danh)) hoi cua tu.
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((mang xa) or (nang ma)) hoi. hieu va cao luc ((va hanh) or (va danh)) hoi cua tu*.