Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
so sang » so sanh, so dang, so lang
sang ky » sang kyo, dang ky, tang ky
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu va » lieu va, hieu qua
cac dac » cac dan, cac dai, cac bac
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sang ky tang xa hoi. hieu va cac dac ((va danh) or (van hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sang ky tang xa hoi. hieu va cac dac ((va danh) OR (van hanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: so sang ky tang xa hoi. hieu va cac dac ((va danh) or (van hanh)) vi cua tre*.