Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, mot chieu
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
bang cong » dang cong, bang song, hang cong
ho chieu » theo chieu, hoc thieu, mot chieu
tinh cua » trinh cua, sinh cua, tinh chat
dan toan » van toan, dan than, manh toan
toan tap » toan ban

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) OR (doi chieu)) sach - hanh tinh cua ((han tong) or (bang cong)) dan toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) sach - hanh tinh cua ((han tong) OR (bang cong)) dan toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (doi chieu)) sach - hanh tinh cua ((han tong) or (bang cong)) dan toan tap".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (doi chieu)) sach - hanh tinh cua ((han tong) or (bang cong)) dan toan tap*.