Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
canh trinh » canh tranh, hanh trinh, anh trinh
canh tinh » hanh tinh, manh tinh, canh tranh
nang cong » nang song, dang cong, bang cong
dan toan » van toan, dan than, manh toan
da nang » cam nang, kha nang, cao nang
van tan » van tuan, van ban, van tai

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 - ((canh trinh) OR (canh tinh)) da nang cong ((dan toan) OR (van tan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chieu sach - ((canh trinh) OR (canh tinh)) da nang cong ((dan toan) or (van tan)) cau~".
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - ((canh trinh) OR (canh tinh)) da nang cong ((dan toan) or (van tan)) cau*.