Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
hanh trang » thanh trung, canh tranh, hanh trinh
trang va » tran van, hang va
cong dan » cong san, huong dan, cong dong
cong tan » cong tac, cong san, cong thanh
toan cao » toan ban, toan tap
va hang » van hang, va nang, va lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chiet tach) OR (chieu sach)) - hanh trang va hang ((cong dan) or (cong tan)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chiet tach) OR (chieu sach)) - hanh trang va hang ((cong dan) OR (cong tan)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chiet tach) OR (chieu sach)) - hanh trang va hang ((cong dan) or (cong tan)) toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chiet tach) OR (chieu sach)) - hanh trang va hang ((cong dan) or (cong tan)) toan cao*.