Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhung cong » thong cong, hang cong, nhung don
hien hanh » dieu hanh
dung cong » dung trong
ngang tan » nganh toan, nang tai, nang tao
dien anh » tieng anh, dien dan
trung va » truong va, trang va, trung ha
tan cao » toan cao, tao cao, tay cao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((dien anh) or (hien hanh)) - thanh trung va ((nhung cong) OR (dung cong)) ngang tan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((dien anh) OR (hien hanh)) - thanh trung va ((nhung cong) OR (dung cong)) ngang tan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((dien anh) or (hien hanh)) - thanh trung va ((nhung cong) OR (dung cong)) ngang tan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((dien anh) or (hien hanh)) - thanh trung va ((nhung cong) OR (dung cong)) ngang tan cao*.