Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu nganh » vien nganh, hiem ngan, nghiep nganh
thong cong » tong cong, thong thong, phong chong
hieu manh » chieu xanh, dieu hanh, hien hanh
trung cua » truong cua, trung tuan, trung cap
san toan » van toan, dan toan, 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: hoc ((hieu manh) or (hieu nganh)) - thanh trung cua ((thong cong) OR (trong cong)) san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (hieu nganh)) - thanh trung cua ((thong cong) OR (trong cong)) san toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) or (hieu nganh)) - thanh trung cua ((thong cong) OR (trong cong)) san toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) or (hieu nganh)) - thanh trung cua ((thong cong) OR (trong cong)) san toan cau*.