Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh quan » tinh quang, trinh luat, trinh han
nhung cong » thong cong, hang cong, nhung don
tieu sang » chieu sang, tieu dung, tiem nang
dung cong » dung trong
can cau » ban cau, ca cau, cac cau
van cau » van dau, van hau, van chat

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: theo tieu sang - hanh trinh quan ((nhung cong) OR (dung cong)) toan ((can cau) OR (van cau))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo tieu sang - hanh trinh quan ((nhung cong) or (dung cong)) toan ((can cau) OR (van cau))~".
• Adding a wildcard symbol may retrieve word variants: theo tieu sang - hanh trinh quan ((nhung cong) or (dung cong)) toan ((can cau) OR (van cau))*.