Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, hieu lang
ho chieu » theo chieu, hoc thieu, doi chieu
hoc taig » hoc tang, hoc dai, hoc tap
cong tac » cong ty
tac than » tac thanh, tam than, tac nhan
than cau » toan cau, phan cau, than cap
hoc tai » hoc dai, hoc tap, hoc bai

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 - thanh trung ((hoc taig) OR (hoc tai)) cong tac than cau~.
• Adding a wildcard symbol may retrieve word variants: ho chieu sang - thanh trung ((hoc taig) or (hoc tai)) cong tac than cau*.