Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, hieu lang
hieu quang » thieu quang, hieu quan, hieu qua
dung cong » dung trong
tra tuan » tran tuan, tri tuan, ta tuan
tra quan » tri quan, tran quang, toan quan
cong tan » cong tac, cong san, cong thanh
tan quan » tang quan, toan quan, van quan
quan tap » quan tai, quan lap, quan tam

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu quang)) - thanh ((tra tuan) OR (tra quan)) dung cong tan quan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (hieu quang)) - thanh ((tra tuan) OR (tra quan)) dung cong tan quan tap~".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu quang)) - thanh ((tra tuan) OR (tra quan)) dung cong tan quan tap*.