Perhaps you should try some spelling variations:
hanh hai » thanh hai, nhanh hai, hang hai
cua tre » cua te, cuu tre, cua triet
cac loc » cac lop, cac toc, cac hoc
dai hoi » dai hoc, dai moi
hai cua » thai cua, dai cua, hoi cua
dai hai » dai han, dai tai, dai thao
hieu ve » hieu van
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
loc va » hoc va, luc va
su sai » su tai, su hai, su dai
sai ky » sac ky

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 hoi) or (dai hai)). ((hieu ve) or (hieu va)) cac loc va hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky nang ((dai hoi) OR (dai hai)). ((hieu ve) OR (hieu va)) cac loc va hanh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sai ky nang ((dai hoi) or (dai hai)). ((hieu ve) or (hieu va)) cac loc va hanh hai cua tre*.