Perhaps you should try some spelling variations:
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
va dinh » van dinh, va kinh, va tinh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
san ky » sang ky, dan ky, ban ky
nang o » nang co, nang ho, nang ro
va cao » va cac, va co, va dao
cao tu » cao thu, co tu, cao su
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((san ky) or (van ky)) nang o hoi. hieu va cao tu ((va hanh) or (va dinh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((san ky) OR (van ky)) nang o hoi. hieu va cao tu ((va hanh) OR (va dinh)) vai cua tre.
• Adding a wildcard symbol may retrieve word variants: te ((san ky) or (van ky)) nang o hoi. hieu va cao tu ((va hanh) or (va dinh)) vai cua tre*.