Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, nghiep nganh
hieu manh » chieu xanh, dieu hanh, hien hanh
huong ben » huong den, cuong bien, huong dan
thanh cac » hanh cac, thanh bac, thanh ca
tranh va » tranh van, trang va, trinh va
cong ben » cong ren, cong bang, cong binh

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)) - canh tranh va nhung ((cong ben) OR (huong ben)) thanh cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (hieu nganh)) - canh tranh va nhung ((cong ben) OR (huong ben)) thanh cac.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) or (hieu nganh)) - canh tranh va nhung ((cong ben) OR (huong ben)) thanh cac".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) or (hieu nganh)) - canh tranh va nhung ((cong ben) OR (huong ben)) thanh cac*.