Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
chieu sang » chieu sach, chieu xanh, hieu lang
thanh dung » thanh duong, thanh tung, thanh hung
nhung cong » dung cong, thong cong, hang cong
cua nhung » va nhung
dung cua » dung luan, dung cho
cong san » cong tac
san tan » van tan, san van, san tay
tan cau » toan cau, van cau, tan ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu quang) or (chieu sang)) - thanh dung cua nhung cong san tan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu quang) OR (chieu sang)) - thanh dung cua nhung cong san tan cau.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu quang) or (chieu sang)) - thanh dung cua nhung cong san tan cau*.