Perhaps you should try some spelling variations:
ban thanh » ban hang
cham duc » pham duc, cham soc, pham duy
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
bac ky » cac ky, ban ky, sac ky
su bac » xu bac, du bac, su cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su bac ky tang xa hoi. ((hieu ve) OR (hieu van)) cham duc ((ban thanh) or (ban hanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su bac ky tang xa hoi. ((hieu ve) OR (hieu van)) cham duc ((ban thanh) OR (ban hanh)) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su bac ky tang xa hoi. ((hieu ve) OR (hieu van)) cham duc ((ban thanh) or (ban hanh)) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: su bac ky tang xa hoi. ((hieu ve) OR (hieu van)) cham duc ((ban thanh) or (ban hanh)) hai cua tre*.