Perhaps you should try some spelling variations:
luat chung » luan chung, luat thuong, cua chung
canh trinh » canh tranh, hanh trinh, canh tinh
cong thanh » dong thanh, cong trinh, cong tan
luat cong » thuat cong, cua cong, luat canh
thanh van » thanh san, thanh toan, thanh phan
doc hieu » toc thieu, hoc thieu, hoc hien

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 qua - canh trinh ((luat cong) or (luat chung)) cong thanh van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu qua - canh trinh ((luat cong) OR (luat chung)) cong thanh van ban.
• Adding a wildcard symbol may retrieve word variants: doc hieu qua - canh trinh ((luat cong) or (luat chung)) cong thanh van ban*.