Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
tranh qua » tranh cua, thanh qua, trinh qua
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
qua dung » quang dung, su dung, qua song
cong dan » cong san, cong tan, huong dan
toan cau » toan ban, toan tap, toan tai
toan cao » toan ban, toan 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 xanh - canh tranh qua dung cong dan ((toan cau) OR (toan cao))~.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - canh tranh qua dung cong dan ((toan cau) or (toan cao))*.