Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
tranh cua » doanh cua, manh cua
duong dan » duong dang, huong dan, duong van
chinh cau » chinh chau, chinh ca, chinh can
hoc hieu » hoc thieu, hoc hien, doc hieu
dong dan » dong danh, dong san, cong dan
chan cau » phan cau, can cau, nhanh 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 hieu manh - canh tranh cua cong ((dong dan) or (duong dan)) ((chan cau) or (chinh cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu manh - canh tranh cua cong ((dong dan) OR (duong dan)) ((chan cau) OR (chinh cau)).
• Adding a wildcard symbol may retrieve word variants: hoc hieu manh - canh tranh cua cong ((dong dan) or (duong dan)) ((chan cau) or (chinh cau))*.