Perhaps you should try some spelling variations:
chiet tach » chieu sach
hanh trang » thanh trung, hanh trinh, minh trang
dung cong » dung trong
ho chiet » ho chieu, ho thiet, hoc thiet
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan cau » toan cao, toan ban, toan tap
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho chiet tach - ((hanh trang) or (canh tranh)) va dung cong bai toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho chiet tach - ((hanh trang) OR (canh tranh)) va dung cong bai toan cau.
• Adding a wildcard symbol may retrieve word variants: ho chiet tach - ((hanh trang) or (canh tranh)) va dung cong bai toan cau*.