Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sang » chieu sang, thieu khang, thieu quang
dien quang » diep quang, trien quang, lien quan
trung tuan » trung thanh, trung tam, tran tuan
tuan duong » tuyen duong, tuong duong, van duong
duong cong » dung cong, luong cong, duong trong
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
toan cau » 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 (dien quang)) - thanh trung tuan duong cong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (dien quang)) - thanh trung tuan duong cong tap toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (dien quang)) - thanh trung tuan duong cong tap toan cau*.