Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, mot chieu
tranh cua » doanh cua, manh cua
ban tuong » ban huong, ban trong, va tuong
tuong bai » tuong lai, cuong bai, thong bai
ho chieu » theo chieu, hoc thieu, mot chieu
bai toan » bai tap
toan ban » van 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)) xanh - canh tranh cua ban tuong bai toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (doi chieu)) xanh - canh tranh cua ban tuong bai toan ban".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (doi chieu)) xanh - canh tranh cua ban tuong bai toan ban*.