Perhaps you should try some spelling variations:
thanh tung » thanh cong
hieu lang » chieu sang, hieu quang, nhieu tang
cua thong » cua thuong, cua khong, cua tong
cong dan » cong san, huong dan, cong dong
cong tan » cong tac, cong san, cong thanh
toan cao » toan ban, toan tap
ho hieu » ho chieu, hoi hieu, nho hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu lang - ((thanh trung) or (thanh tung)) cua thong ((cong dan) OR (cong tan)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - ((thanh trung) OR (thanh tung)) cua thong ((cong dan) OR (cong tan)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu lang - ((thanh trung) or (thanh tung)) cua thong ((cong dan) OR (cong tan)) toan cao".
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - ((thanh trung) or (thanh tung)) cua thong ((cong dan) OR (cong tan)) toan cao*.