Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
hanh tranh » canh tranh, hanh trinh, hanh trang
doi chieu » doc hieu, doi chi, ho chieu
tranh cua » doanh cua, manh cua
dung cong » dung trong
cua dung » cua dang, cua dong, qua dung
tap toan » tap quan, bai toan
tap doan » tap quan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((theo chieu) or (doi chieu)) xanh - hanh tranh cua dung cong ((tap toan) OR (tap doan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chieu) OR (doi chieu)) xanh - hanh tranh cua dung cong ((tap toan) OR (tap doan)) cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) or (doi chieu)) xanh - hanh tranh cua dung cong ((tap toan) OR (tap doan)) cau*".