Perhaps you should try some spelling variations:
thieu quang » hieu quang, thien quan, trien quang
thanh trung » thanh tung
thieu sang » chieu sang, thieu khang, hieu lang
trung cap » truong cao, trung tam
dong cong » duong cong, dung cong, dang cong
cap dong » cao dong, cau dong, ca dong
tam toan » tam than, pham toan, tam thanh
tap toan » tap doan, tap quan, bai toan

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