Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
hanh tranh » canh tranh, hanh trinh, hanh trang
hoc thieu » toc thieu, hoc hien
chua bang » chu bang, chua nang, thuat bang
chua xang » chua nang, chuc nang, chu bang
cong tan » cong tac, cong san, cong thanh
bang cau » hang cau, bang cac, nang cao
ban cau » ban can, van cau, ban dau

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 - hanh tranh ((chua bang) OR (chua xang)) cong tan ((ban cau) OR (bang cau))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sang - hanh tranh ((chua bang) or (chua xang)) cong tan ((ban cau) OR (bang cau))~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - hanh tranh ((chua bang) or (chua xang)) cong tan ((ban cau) OR (bang cau))*.