Perhaps you should try some spelling variations:
hanh trang » thanh trung, canh tranh, hanh trinh
chiet tach » chieu sach
hieu sach » chieu sach, hieu cach, dien sach
cua dang » cua ban
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sach) or (chiet tach)) - hanh trang ((cua dang) or (cua cong)) cong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (chiet tach)) - hanh trang ((cua dang) OR (cua cong)) cong dan toan cau.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) or (chiet tach)) - hanh trang ((cua dang) or (cua cong)) cong dan toan cau*.