Perhaps you should try some spelling variations:
va dinh » van dinh, va kinh, va tinh
va hanh » van hanh, va thanh, va danh
sang ky » sang kyo, dang ky, tang ky
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
cam tu » cam thu, nam tu, dam tu
dan ky » van ky
vi cua » vai cua, di cua
va cam » va cham, va cac, va cao
x hoi » xa hoi, o hoi, x ho

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

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