Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hanh dai » hanh tai, hanh dao, vanh dai
ban hanh » ban hang
chat hoc » chat hoa, chat thom, cho hoc
dai cau » dat cau, da cau, dai hau
cuc ban » cua ban, cac ban, cuu ban
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoc » co hoc, cho hoc
va cam » va cham, va cac, va cao
ve cac » va cac, vien cac

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 cac) or (va cam)) cuc ban hanh dai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((cao hoc) OR (chat hoc)). hieu ((ve cac) OR (va cam)) cuc ban hanh dai cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((cao hoc) or (chat hoc)). hieu ((ve cac) or (va cam)) cuc ban hanh dai cau tren*.