Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
doi chieu » doi chi, ho chieu, mot chieu
trong ban » trong san, trong tan, trong quan
doc hieu » toc thieu, hoc thieu, hoc hien
cua dung » cua dong, qua dung, cua rung
cua dang » cua cong, cua ban
ban toan » bai toan, ban than, van toan
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: ((doi chieu) or (doc hieu)) xanh - hanh tranh ((cua dung) OR (cua dang)) trong ban toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doc hieu)) xanh - hanh tranh ((cua dung) OR (cua dang)) trong ban toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) or (doc hieu)) xanh - hanh tranh ((cua dung) OR (cua dang)) trong ban toan cao".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (doc hieu)) xanh - hanh tranh ((cua dung) OR (cua dang)) trong ban toan cao*.