Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
dai thao » thi thao, dai han
hanh hai » thanh hai, nhanh hai, hang hai
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
vien cac » vien bach, vien dai, vien da
hai cua » thai cua, dai cua, hoi cua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
dai hai » dai han, dai tai, dai nhat
dai hoi » dai hoc, dai moi
sai ky » sac ky
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 hoi) or (((dai hai) or (dai thao)))). hieu vien cac nuoc 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) OR (dai thao)))). hieu vien cac nuoc va hanh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sai ky nang ((dai hoi) or (((dai hai) or (dai thao)))). hieu vien cac nuoc va hanh hai cua tre*.