Perhaps you should try some spelling variations:
chiet tach » chieu sach
hanh trinh » canh tranh, hanh chinh
cac chuong » cac phuong, cac chung, cac cong
hoc chiet » hoc thiet, hoc nhiet, hoc hien
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
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: hoc chiet tach - hanh trinh ((cac chuong) or (cac truong)) cong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chiet tach - hanh trinh ((cac chuong) OR (cac truong)) cong dan toan cao*.