Perhaps you should try some spelling variations:
bang hang » ban hang, hang hang, nang hang
cham hoc » chat hoc, cham hoi, cho hoc
te sach » toc sach
hang le » hoang le, tang le, hang ly
hieu ve » hieu va, hieu van
dai moi » doi moi, dai hoi
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, v nang, may nang
le cua » ly 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 ((y nang) or (ly nang)) dai moi. hieu ve ((cham hoc) or (cham soc)) bang hang le cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((y nang) OR (ly nang)) dai moi. hieu ve ((cham hoc) OR (cham soc)) bang hang le cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ((y nang) or (ly nang)) dai moi. hieu ve ((cham hoc) or (cham soc)) bang hang le cua tre*.