Perhaps you should try some spelling variations:
va hanh » van hanh, va thanh, va danh
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
va dinh » van dinh, va kinh, va tinh
hieu va » lieu va, hieu qua
cao luc » bao luc, cao duc, cao suc
tu san » thu san, tu ban, tu can
vi cua » vai cua, di cua
va cao » va cac, va co, va dao
san ky » sang ky, van ky, dan ky
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 san ky ((nang xa) or (nang ma)) hoi. hieu va cao luc ((va hanh) or (va dinh)) vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky ((nang xa) OR (nang ma)) hoi. hieu va cao luc ((va hanh) OR (va dinh)) vi cua te.
• Adding a wildcard symbol may retrieve word variants: tu san ky ((nang xa) or (nang ma)) hoi. hieu va cao luc ((va hanh) or (va dinh)) vi cua te*.