Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
hanh tang » hanh trang, anh tang, hanh mang
hoc hieu » hoc thieu, hoc hien, doc hieu
cua tong » cua cong, cua nong, cua song
cua dong » chua dong, cua cong, cua dang
cong tan » cong tac, cong san, cong thanh
tan than » tan thanh, tan tran, ban than
than cau » toan cau, phan cau, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu manh - hanh tang ((cua tong) or (cua dong)) cong tan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu manh - hanh tang ((cua tong) OR (cua dong)) cong tan than cau.
• Adding a wildcard symbol may retrieve word variants: hoc hieu manh - hanh tang ((cua tong) or (cua dong)) cong tan than cau*.