Perhaps you should try some spelling variations:
cham sao » cham vao, cham soc, nam sao
ban hanh » ban hang
ky tang » ky nang, ky dang, kho tang
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
va cham » va chat, va tham
sao ban » tao ban, cao bang, tao bang
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi
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 ky tang ((ma hoi) OR (mai hoi)). hieu va cham sao ban hanh vi cua tre~.
• Adding a wildcard symbol may retrieve word variants: tu cac ky tang ((ma hoi) or (mai hoi)). hieu va cham sao ban hanh vi cua tre*.