Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
dung cong » dung trong
hang cong » dang cong, hang nong, bang cong
hoc hieu » hoc thieu, hoc hien, doc hieu
tranh va » tranh van, trang va, trinh va
van toan » van tuan, van tan, van thanh
toan cau » toan cao, toan ban, toan tap

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 va ((dung cong) or (hang cong)) van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu manh - canh tranh va ((dung cong) OR (hang cong)) van toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc hieu manh - canh tranh va ((dung cong) or (hang cong)) van toan cau*.