Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
tranh qua » tranh cua, thanh qua, trinh qua
hoc hieu » hoc thieu, hoc hien, doc hieu
qua dung » quang dung, su dung, qua song
than cao » toan cao, than cap, than sao
thai cao » tai cao, thoai cac, thuat cao
cong cu » chung cu

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 qua dung ((cong cu) or (cong ty)) ((than cao) OR (thai cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu manh - canh tranh qua dung ((cong cu) OR (cong ty)) ((than cao) OR (thai cao)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu manh - canh tranh qua dung ((cong cu) or (cong ty)) ((than cao) OR (thai cao))".
• Adding a wildcard symbol may retrieve word variants: hoc hieu manh - canh tranh qua dung ((cong cu) or (cong ty)) ((than cao) OR (thai cao))*.