Perhaps you should try some spelling variations:
bang hang » ban hang, hang hang, nang hang
cham hoc » cham soc, chat hoc, cham hoi
hoc bang » hoc bong, hoc tang, hoc dan
te sach » toc sach
sach ky » sac ky, sach y, sach ty
mai doi » moi doi, mai hoi, mai khoi
dai hoi » dai hoc, dai hai, dai moi
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang ((mai doi) or (dai hoi)). hieu ve cham hoc bang hang va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((mai doi) OR (dai hoi)). hieu ve cham hoc bang hang va cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((mai doi) or (dai hoi)). hieu ve cham hoc bang hang va cua tre*.