Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
quan thanh » ban thanh, van thanh
quan hanh » quang thanh, quang khanh, quan hoang
ho chieu » theo chieu, hoc thieu, doi chieu
theo chu » theo chieu, cho chu, chao chu
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan cau » 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: ((ho chieu) OR (theo chu)) xanh - canh trinh ((quan hanh) OR (quan thanh)) cong san toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (theo chu)) xanh - canh trinh ((quan hanh) OR (quan thanh)) cong san toan cau~".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (theo chu)) xanh - canh trinh ((quan hanh) OR (quan thanh)) cong san toan cau*.