Perhaps you should try some spelling variations:
cham hoc » cham soc, chat hoc, cham hoi
cua tre » cua te, cuu tre, cua triet
hanh va » hanh vi
hoc ban » hoc bang, hoc dan, hoc bai
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
sac ky » cac ky, sai ky
te sac » te sach, te cac, te san

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

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