Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
truong cao » truong dai
nhung cong » dung cong, thong cong, hang cong
hieu xanh » chieu xanh, hieu manh, dieu hanh
trung cap » trung tam
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
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: doc ((hieu xanh) or (hieu nganh)) - hanh ((trung cap) OR (truong cao)) nhung cong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu xanh) OR (hieu nganh)) - hanh ((trung cap) OR (truong cao)) nhung cong dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu xanh) or (hieu nganh)) - hanh ((trung cap) OR (truong cao)) nhung cong dan toan cau".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu xanh) or (hieu nganh)) - hanh ((trung cap) OR (truong cao)) nhung cong dan toan cau*.