Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hieu manh » chieu xanh, hieu nganh, dieu hanh
hanh tran » hanh trang, thanh tran, hanh tram
tran van » luan van
van hang » van khang, van hoang, van thang
cong tac » cong ty
tran huu » tran duc

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu manh) or (chieu sach)) - hanh tran van hang ((cong san) OR (cong tac)) tran huu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu manh) OR (chieu sach)) - hanh tran van hang ((cong san) OR (cong tac)) tran huu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu manh) or (chieu sach)) - hanh tran van hang ((cong san) OR (cong tac)) tran huu".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu manh) or (chieu sach)) - hanh tran van hang ((cong san) OR (cong tac)) tran huu*.