Perhaps you should try some spelling variations:
ban hanh » ban hang
cac khoa » cac khoan, cac khoi, dac khoa
cac kho » cac khoi, cac khu, cac ho
hieu ve » hieu va, hieu van
dai hoi » dai hoc, dai hai, dai moi
tai hoi » tai khoi, tai hai, tai hoe
cua tre » cua te, cuu tre, cua triet
ve ham » ve cham, le ham, ve am
ham so » nam so, cham soc
so ban » sao ban, so bang, co ban
vi cua » vai cua, di cua

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 kho) OR (cac khoa)) tang ((tai hoi) OR (dai hoi)). hieu ve ham so ban hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((cac kho) OR (cac khoa)) tang ((tai hoi) or (dai hoi)). hieu ve ham so ban hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu ((cac kho) OR (cac khoa)) tang ((tai hoi) or (dai hoi)). hieu ve ham so ban hanh vi cua tre*.