Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
hieu ve » hieu van
dai moi » doi moi, dai hoi
dai hai » dai han, dai hoi, dai tai
sai ky » sac ky
luc va » duc va, tuc va, loc va
su sai » su tai, su hai, su dai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ky nang ((dai moi) or (dai hai)). ((hieu ve) or (hieu va)) coc luc va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky nang ((dai moi) OR (dai hai)). ((hieu ve) OR (hieu va)) coc luc va hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sai ky nang ((dai moi) or (dai hai)). ((hieu ve) or (hieu va)) coc luc va hanh dai cua tre*.