Perhaps you should try some spelling variations:
chiet tach » chieu sach
hanh trang » thanh trung, canh tranh, hanh trinh
hoc chiet » hoc thiet, hoc nhiet, hoc hien
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 - 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 - hanh trang va hang ((cong dan) OR (cong tan)) toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - hanh trang va hang ((cong dan) or (cong tan)) toan cao*.