Perhaps you should try some spelling variations:
cong luong » cong thuong, nang luong, cong dong
hieu lang » chieu sang, hieu quang, nhieu tang
doi hieu » doi chieu, doc hieu, doi hien
hang ban » hang luan, hang va, hang tai
va thong » va thuong, va phuong, he thong
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 lang - hang ban va thong ((cong san) or (cong luong)) tuan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - hang ban va thong ((cong san) OR (cong luong)) tuan cau.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hang ban va thong ((cong san) or (cong luong)) tuan cau*.