Perhaps you should try some spelling variations:
hieu sang » chieu sang, hieu lang, hieu quang
canh manh » lanh manh, canh tranh, cach mang
dong cong » duong cong, dung cong, dang cong
doc hieu » toc thieu, hoc thieu, hoc hien
manh cua » doanh cua, ban cua
cua dong » chua dong, cua cong, cua dang
cong ban » cong bang, cong san, cong tan
chan cau » phan cau, chinh cau, nhanh cau
can cau » van cau, ca cau, cac cau
ban cau » bang cau, ban can, van cau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu sang - canh manh cua dong cong ban ((chan cau) or (((can cau) or (ban cau))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - canh manh cua dong cong ban ((chan cau) OR (((can cau) OR (ban cau)))).
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - canh manh cua dong cong ban ((chan cau) or (((can cau) or (ban cau))))*.