Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
tranh qua » tranh cua, thanh qua, trinh qua
dung cong » dung trong
qua dung » quang dung, su dung, qua song
dan toan » van toan, dan than, manh toan

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 (chieu sang)) - hanh tranh qua dung cong ((dan toan) or (tinh toan)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hieu lang) OR (chieu sang)) - hanh tranh qua dung cong ((dan toan) OR (tinh toan)) tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hieu lang) OR (chieu sang)) - hanh tranh qua dung cong ((dan toan) or (tinh toan)) tap".
• Adding a wildcard symbol may retrieve word variants: theo ((hieu lang) OR (chieu sang)) - hanh tranh qua dung cong ((dan toan) or (tinh toan)) tap*.