Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hanh trung » thanh trung, manh trung, danh trung
hanh trang » thanh trung, canh tranh, hanh trinh
tuan trong » thuan trong, quan trong, tran trong
hieu lang » chieu sang, nhieu tang, hieu van
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: theo ((hieu lang) OR (hieu quang)) - ((hanh trung) or (hanh trang)) tuan trong cong san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hieu lang) OR (hieu quang)) - ((hanh trung) OR (hanh trang)) tuan trong cong san toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hieu lang) OR (hieu quang)) - ((hanh trung) or (hanh trang)) tuan trong cong san toan cau".
• Adding a wildcard symbol may retrieve word variants: theo ((hieu lang) OR (hieu quang)) - ((hanh trung) or (hanh trang)) tuan trong cong san toan cau*.