Perhaps you should try some spelling variations:
ban thanh » ban hang
ban hanh » ban hang
cua tre » cua te, cuu tre, cua triet
tai cua » thai cua, tai cuc, tri cua
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
sai ky » sac ky
ve cac » va cac, vien 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 ((cac ky) or (sai ky)) tang xa hoi. hieu ve cac duc ((ban thanh) or (ban hanh)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((cac ky) OR (sai ky)) tang xa hoi. hieu ve cac duc ((ban thanh) OR (ban hanh)) tai cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((cac ky) or (sai ky)) tang xa hoi. hieu ve cac duc ((ban thanh) or (ban hanh)) tai cua tre*.