Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thanh trang » thanh trung, hanh trang, thanh thang
thieu sang » chieu sang, thieu quang, hieu lang
trang va » tran van, hang va
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sang) or (thieu khang)) - thanh trang va thuong ((cong tan) OR (cong tac)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu khang)) - thanh trang va thuong ((cong tan) OR (cong tac)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (thieu khang)) - thanh trang va thuong ((cong tan) OR (cong tac)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (thieu khang)) - thanh trang va thuong ((cong tan) OR (cong tac)) toan cau*.