Perhaps you should try some spelling variations:
duong duong » tuong duong, cuong duong, dong duong
hieu quang » thieu quang, hieu quan, hieu qua
chieu sang » chieu sach, chieu xanh, hieu lang
duong anh » duong manh, duong xanh, duong vanh
tranh va » tranh van, trang va, trinh va
va duong » van duong, va tuong, va huong
tuan cau » toan cau, quan cau, tuan cu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu quang) or (chieu sang)) - canh tranh va duong duong anh tuan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu quang) OR (chieu sang)) - canh tranh va duong duong anh tuan cau.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu quang) or (chieu sang)) - canh tranh va duong duong anh tuan cau*.