Perhaps you should try some spelling variations:
chieu sach » chiet tach, chieu sang, chieu xanh
canh trinh » canh tranh, hanh trinh, canh tinh
trinh khai » trinh kham, trinh han, trinh tai
khai nang » kha nang, chai nang, khai sang
nang cong » nang song, dang cong, bang cong
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (chinh sach)) - canh trinh khai nang cong dan toan cau~.
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) or (chinh sach)) - canh trinh khai nang cong dan toan cau*.