Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
ban hanh » ban hang
chat hoc » chat hoa, chat thom, cho hoc
tu sach » thu sach, su sach, te sach
cuc ban » cua ban, cac ban, cuu ban
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
cao hoc » co hoc, cho hoc
va cam » va cham, va cac, va cao
ve cam » ve cham, ve cac, ve cai

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

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