Perhaps you should try some spelling variations:
thanh tuong » thanh thuong, thanh tung, thanh huong
thieu sang » chieu sang, thieu khang, thieu quang
hoc thieu » toc thieu, hoc hien
tuong cua » truong cua, huong cua, thong cua
cua tong » cua cong, cua dong, cua nong
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
toan cau » toan cao, toan ban, toan tap

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: hoc thieu sang - thanh tuong cua tong ((cong tan) OR (cong san)) toan cau~.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - thanh tuong cua tong ((cong tan) or (cong san)) toan cau*.