Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
thu sac » thu sach, thu san, thu xac
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
sac ky » cac ky, sai ky
cac lo » cac lop, cac co, cac bo
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky nang ((x hoi) OR (o hoi)). hieu va cac lo ((va hanh) or (va thanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky nang ((x hoi) OR (o hoi)). hieu va cac lo ((va hanh) OR (va thanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky nang ((x hoi) OR (o hoi)). hieu va cac lo ((va hanh) or (va thanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sac ky nang ((x hoi) OR (o hoi)). hieu va cac lo ((va hanh) or (va thanh)) vai cua tre*.