Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
duong manh » duong van
manh toan » thanh toan, anh tuan, tinh toan
doc hieu » toc thieu, hoc thieu, hoc hien
van dung » van dong, xay dung, tin dung
toan ban » van ban
va dung » va duong, vat dung, va ung

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (theo tieu)) xanh - hanh tranh ((va dung) OR (van dung)) duong manh toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (theo tieu)) xanh - hanh tranh ((va dung) OR (van dung)) duong manh toan ban~".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (theo tieu)) xanh - hanh tranh ((va dung) OR (van dung)) duong manh toan ban*.