Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
tung cao » truong cao, trung cap, quang cao
nung cao » nang cao, nhung cau, quang cao
ung cong » dung cong, luong cong, duong cong
cong san » cong tac
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: doi ((hieu lang) or (hieu quang)) - thanh ((tung cao) OR (nung cao)) ung cong san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((hieu lang) OR (hieu quang)) - thanh ((tung cao) OR (nung cao)) ung cong san toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((hieu lang) or (hieu quang)) - thanh ((tung cao) OR (nung cao)) ung cong san toan cau".
• Adding a wildcard symbol may retrieve word variants: doi ((hieu lang) or (hieu quang)) - thanh ((tung cao) OR (nung cao)) ung cong san toan cau*.