Perhaps you should try some spelling variations:
ky tang » ky nang, ky dang, kho tang
so bang » so dang, so lang, co bang
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
dai hoi » dai hoc, dai hai, dai moi
tai hoi » tai khoi, tai hai, tai hoe
so ban » sao ban, co ban, lo ban
vi cua » vai cua, di cua
ve ham » ve cham, le ham, ve am

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky tang ((tai hoi) OR (dai hoi)). hieu ve ham ((so ban) OR (so bang)) hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky tang ((tai hoi) or (dai hoi)). hieu ve ham ((so ban) OR (so bang)) hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu cac ky tang ((tai hoi) or (dai hoi)). hieu ve ham ((so ban) OR (so bang)) hanh vi cua tre*.