Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hanh trung » thanh trung, manh trung, danh trung
hanh trang » thanh trung, canh tranh, hanh trinh
tuan dang » tran dang, tuan bang, tuan dung
dang cong » dung cong
ho chieu » theo chieu, hoc thieu, doi chieu
tac toan » tap toan, hach toan, tich toan
tam toan » tap toan, tam than, pham toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho chieu sach - ((hanh trung) or (hanh trang)) tuan dang cong ((tac toan) OR (tam toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu sach - ((hanh trung) OR (hanh trang)) tuan dang cong ((tac toan) OR (tam toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu sach - ((hanh trung) or (hanh trang)) tuan dang cong ((tac toan) OR (tam toan)) cau".
• Adding a wildcard symbol may retrieve word variants: ho chieu sach - ((hanh trung) or (hanh trang)) tuan dang cong ((tac toan) OR (tam toan)) cau*.