Perhaps you should try some spelling variations:
thieu sang » thieu khang, thieu quang, hieu lang
chieu sang » chieu sach, chieu xanh, hieu lang
thanh dung » thanh duong, thanh tung, thanh hung
luan nhung » luan chung, luan hung, quan nhung
cong dan » cong san, cong tan, cong dong
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 (chieu sang)) - thanh dung luan nhung ((cong dan) OR (huong dan)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (chieu sang)) - thanh dung luan nhung ((cong dan) OR (huong dan)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (chieu sang)) - thanh dung luan nhung ((cong dan) OR (huong dan)) toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (chieu sang)) - thanh dung luan nhung ((cong dan) OR (huong dan)) toan cao*.