Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
thi chieu » thi chien, thi hieu, theo chieu
ho chieu » theo chieu, hoc thieu, doi chieu
cua dang » cua cong
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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 (thi chieu)) xanh - hanh tranh ((cua dang) or (cua ban)) cong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (thi chieu)) xanh - hanh tranh ((cua dang) OR (cua ban)) cong tap toan cau.
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (thi chieu)) xanh - hanh tranh ((cua dang) or (cua ban)) cong tap toan cau*.