Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
mong luan » tong luan, cong luan, dong luan
bang luan » tang luan, hang luan, dung luan
doc hieu » toc thieu, hoc thieu, hoc hien
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
than cau » toan cau, phan cau, than cap

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 xanh - hanh ((mong luan) OR (bang luan)) dong ((cong dan) OR (cong san)) than cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - hanh ((mong luan) or (bang luan)) dong ((cong dan) OR (cong san)) than cau~".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh ((mong luan) or (bang luan)) dong ((cong dan) OR (cong san)) than cau*.