Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, nghiep nganh
hanh trinh » canh tranh, hanh chinh
hieu manh » chieu xanh, dieu hanh, hien hanh
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
trinh va » trinh van, trinh vat, trinh ve
van toan » van tuan, van tan, van thanh
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) OR (hieu nganh)) - hanh trinh va ((hang cong) or (dang cong)) van toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (hieu nganh)) - hanh trinh va ((hang cong) OR (dang cong)) van toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) OR (hieu nganh)) - hanh trinh va ((hang cong) or (dang cong)) van toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) OR (hieu nganh)) - hanh trinh va ((hang cong) or (dang cong)) van toan cao*.