Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
thanh tung » thanh cong
nhung cong » dung cong, thong cong, hang cong
thanh chau » thanh cha, thanh cham, thanh chu
hoc thieu » toc thieu, hoc hien
cua nhung » va nhung
cong tan » cong tac, cong san, cong thanh
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 trung) OR (thanh tung)) cua nhung cong tan ((thanh chau) OR (toan cao))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sang - ((thanh trung) OR (thanh tung)) cua nhung cong tan ((thanh chau) or (toan cao))~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - ((thanh trung) OR (thanh tung)) cua nhung cong tan ((thanh chau) or (toan cao))*.