Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thieu sang » chieu sang, thieu quang, hieu lang
dang cong » dung cong
tranh va » tranh van, trang va, trinh va
tac phan » tai phan, tac phat, cac phan
tac pham » thuc pham, san pham
va dang » van dang, va nang, va lang

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)) - canh tranh va dang cong ((tac phan) OR (tac pham)) dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu khang)) - canh tranh va dang cong ((tac phan) OR (tac pham)) dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (thieu khang)) - canh tranh va dang cong ((tac phan) OR (tac pham)) dau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (thieu khang)) - canh tranh va dang cong ((tac phan) OR (tac pham)) dau*.