Perhaps you should try some spelling variations:
trinh tan » trinh toan, trinh tuan, trinh han
van quang » van quan, tran quang, van tuan
ho chieu » theo chieu, hoc thieu, doi chieu
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
toan cao » toan ban, toan tap
tan van » tran van, tang van, luan van

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 tieu)) xanh - trinh tan van quang ((cong tan) OR (cong tac)) toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (theo tieu)) xanh - trinh tan van quang ((cong tan) OR (cong tac)) toan cao~".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (theo tieu)) xanh - trinh tan van quang ((cong tan) OR (cong tac)) toan cao*.