Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
tranh cua » doanh cua, manh cua
dong cong » duong cong, dung cong, dang cong
hach toan » thanh toan, manh toan
doc hieu » toc thieu, hoc thieu, hoc hien
cua dong » chua dong, cua cong, cua dang
bai toan » bai tap

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 manh - canh tranh cua dong cong ((hach toan) OR (bai toan)) cao~.
• Adding a wildcard symbol may retrieve word variants: doc hieu manh - canh tranh cua dong cong ((hach toan) or (bai toan)) cao*.