Perhaps you should try some spelling variations:
ban hanh » ban hang
cua tre » cua te, cuu tre, cua triet
duc ban » duc tan, duc van, dua ban
va cham » va chat, va tham
ve cham » ve chat, vu cham, ve chim
mai hoi » mai khoi, dai hoi, lai hoi
sai ky » sac ky
ma hoi » xa hoi, ma hoa, me hoi
vi cua » vai cua, di cua
tu sai » tu bai, tu san, tu cai

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 sai ky nang ((ma hoi) OR (mai hoi)). hieu ((ve cham) OR (va cham)) duc ban hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky nang ((ma hoi) or (mai hoi)). hieu ((ve cham) OR (va cham)) duc ban hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sai ky nang ((ma hoi) or (mai hoi)). hieu ((ve cham) OR (va cham)) duc ban hanh vi cua tre*.