Perhaps you should try some spelling variations:
cham hoc » cham soc, cham hoi, cho hoc
ban hanh » ban hang
chat hoc » chat hoa, chat thom, cho hoc
te sach » toc sach
hanh va » hang va, hanh vi
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
dai hoi » dai hoc, dai hai, dai moi
mai hoi » mai khoi, lai hoi, mai doi
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 hoi) or (dai hoi)). hieu ve ((cham hoc) OR (chat hoc)) ban hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((mai hoi) OR (dai hoi)). hieu ve ((cham hoc) OR (chat hoc)) ban hanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((mai hoi) or (dai hoi)). hieu ve ((cham hoc) OR (chat hoc)) ban hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((mai hoi) or (dai hoi)). hieu ve ((cham hoc) OR (chat hoc)) ban hanh va cua tre*.