Perhaps you should try some spelling variations:
dang hai » dang khai, hang hai, dung hai
danh hai » lanh hai, manh hai, danh hau
cua tre » cua te, cuu tre, cua triet
tai hoi » tai khoi, tai hai, tai hoe
dai hoi » dai hoc, dai hai, dai moi
hieu ve » hieu va, hieu van
cac luc » cau luc, coc luc, cac nuoc
su sai » su tai, su hai, su dai
luc va » duc va, tuc va, loc va
sai ky » sac ky
ve cac » va cac, vien cac

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