Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thanh dung » thanh duong, thanh tung, thanh hung
hieu lang » chieu sang, hieu quang, nhieu tang
cong van » cong vang, song van, cong tan
cong san » cong tac
toan cao » toan ban, toan tap
va bang » va nang, va lang, va ban

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

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