Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
cong luong » cong thuong, nang luong, cong dong
doi hieu » doi chieu, doc hieu, doi hien
hanh ban » thanh ban, hang ban, hanh san
va thong » va phuong, he thong, va cong
cong san » cong tac
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: doi hieu quang - hanh ban ((va thong) OR (va thuong)) ((cong san) or (cong luong)) tuan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu quang - hanh ban ((va thong) OR (va thuong)) ((cong san) OR (cong luong)) tuan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu quang - hanh ban ((va thong) OR (va thuong)) ((cong san) or (cong luong)) tuan cau".
• Adding a wildcard symbol may retrieve word variants: doi hieu quang - hanh ban ((va thong) OR (va thuong)) ((cong san) or (cong luong)) tuan cau*.