Perhaps you should try some spelling variations:
ban hanh » ban hang
kho tang » cao tang
ky tang » ky nang, ky dang, ky trong
cham so » cham soc, cham o, ham so
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
dai hoi » dai hoc, dai hai, dai moi
mai hoi » mai khoi, lai hoi, mai doi
cua tre » cua te, cuu tre, cua triet
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.

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ((ky tang) or (kho tang)) ((mai hoi) OR (dai hoi)). hieu ve cham so ban hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ((ky tang) OR (kho tang)) ((mai hoi) OR (dai hoi)). hieu ve cham so ban hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ((ky tang) or (kho tang)) ((mai hoi) OR (dai hoi)). hieu ve cham so ban hanh vi cua tre*".