Perhaps you should try some spelling variations:
thieu quang » hieu quang, thien quan, trien quang
thanh trung » thanh tung
trung thanh » truong thanh
thieu sang » chieu sang, thieu khang, hieu lang
nhung cong » thong cong, hang cong, nhung don
dung cong » dung trong
ban than » ban thanh, van thanh, ban hang
than cau » toan cau, phan cau, than cap

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 quang)) - thanh trung thanh ((nhung cong) OR (dung cong)) ban than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu quang)) - thanh trung thanh ((nhung cong) OR (dung cong)) ban than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (thieu quang)) - thanh trung thanh ((nhung cong) OR (dung cong)) ban than cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (thieu quang)) - thanh trung thanh ((nhung cong) OR (dung cong)) ban than cau*.