Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
cong luong » cong thuong, nang luong, cong dong
thanh ban » thanh san, thanh van, thanh bac
doi hieu » doi chieu, doi hien, hoi hieu
doc hieu » toc thieu, hoc thieu, hoc hien
va thong » va thuong, va phuong, he thong
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) or (doc hieu)) lang - thanh ban va thong ((cong thanh) or (cong luong)) tuan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi hieu) OR (doc hieu)) lang - thanh ban va thong ((cong thanh) OR (cong luong)) tuan cau.
• Adding a wildcard symbol may retrieve word variants: ((doi hieu) or (doc hieu)) lang - thanh ban va thong ((cong thanh) or (cong luong)) tuan cau*.