Perhaps you should try some spelling variations:
nhieu tang » chieu sang, hieu lang, nhiet nang
thanh tung » thanh cong
cong quang » luong quang, thong quang, duong quang
dang cong » dung cong
hieu van » hieu va, thien van, lieu va
tung cao » nung cao, truong cao, trung cap
ban hanh » ban hang
ban cau » bang cau, ban can, van cau

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: doi ((hieu van) OR (nhieu tang)) - thanh tung cao dang cong quang ((ban cau) OR (ban hanh))~.
• Adding a wildcard symbol may retrieve word variants: doi ((hieu van) or (nhieu tang)) - thanh tung cao dang cong quang ((ban cau) or (ban hanh))*.