Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hoc thien » hoc hien, hoc thieu, hoc thiet
anh tang » anh bang, anh dang, anh nang
tang cua » mang cua, hang cua, tang luan
cua bang » chua bang, cua ban, cua dang
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
tran cau » tran chau, toan cau, ran cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thien hach - anh tang cua bang ((cong tan) or (cong tac)) tran cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thien hach - anh tang cua bang ((cong tan) OR (cong tac)) tran cau.
• Adding a wildcard symbol may retrieve word variants: hoc thien hach - anh tang cua bang ((cong tan) or (cong tac)) tran cau*.