Perhaps you should try some spelling variations:
thong quang » thong quan, thong qua, luong quang
chieu sang » chieu sach, chieu xanh, hieu lang
trung quan » truong quan, trong quan, trung tuan
doi chieu » doc hieu, doi chi, ho chieu
trong tap » trong thap, tong tap, trong tan
tap doan » tap quan
doan cau » toan cau, doan dau, doan cap

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 chieu sang - hanh ((trung quan) OR (thong quang)) dung trong tap doan cau~.
• Adding a wildcard symbol may retrieve word variants: doi chieu sang - hanh ((trung quan) or (thong quang)) dung trong tap doan cau*.