Perhaps you should try some spelling variations:
theo chieu » ho chieu, theo chu, thi chieu
hanh tang » hanh trang, anh tang, hanh mang
hang cong » dang cong, hang nong, bang cong
cong cong » cong dong, trong cong, dung cong
tang cua » mang cua, hang cua, tang luan
tac toan » tap toan, tam toan, hach 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) OR (theo tieu)) sach - hanh tang cua ((hang cong) OR (cong cong)) tac toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) OR (theo tieu)) sach - hanh tang cua ((hang cong) or (cong cong)) tac toan cau~".
• Adding a wildcard symbol may retrieve word variants: ((theo chieu) OR (theo tieu)) sach - hanh tang cua ((hang cong) or (cong cong)) tac toan cau*.