Perhaps you should try some spelling variations:
trien quang » tran quang, tuyen quang, dien quang
thanh trung » thanh tung
thieu sang » chieu sang, thieu khang, thieu quang
trung cua » truong cua, trung tuan, trung cap
cong vang » cong quang, cong ngang, cong san
cong lang » cong luong, cong quang, cong ngang
dang bang » dong bang, dang dang, tang bang
cua dung » cua dang, cua dong, qua dung

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