Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, mot chieu
dung cong » dung trong
ho chieu » theo chieu, hoc thieu, mot chieu
tra tuan » tran tuan, tri tuan, ta tuan
tra quan » tri quan, tran quang, toan quan
cong tan » cong tac, cong san, cong thanh
tran cau » tran chau, toan cau, ran cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) OR (doi chieu)) xanh - thanh ((tra tuan) or (tra quan)) dung cong tan tran cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) xanh - thanh ((tra tuan) OR (tra quan)) dung cong tan tran cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (doi chieu)) xanh - thanh ((tra tuan) or (tra quan)) dung cong tan tran cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (doi chieu)) xanh - thanh ((tra tuan) or (tra quan)) dung cong tan tran cau*.