Perhaps you should try some spelling variations:
thanh trong » thanh trung, tranh trong, hanh trong
cong thanh » dong thanh, cong trinh, truong thanh
hieu manh » chieu xanh, hieu nganh, dieu hanh
thien anh » thien danh, tien anh, thien thanh
trong san » trong cac, cong san, dong san
san dung » van dung, dan dung, lan dung
cong tan » cong tac, cong san, cong ty
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 (thien anh)) - thanh trong san dung ((cong tan) OR (cong thanh)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (thien anh)) - thanh trong san dung ((cong tan) OR (cong thanh)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) or (thien anh)) - thanh trong san dung ((cong tan) OR (cong thanh)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) or (thien anh)) - thanh trong san dung ((cong tan) OR (cong thanh)) toan cau*.