Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
trinh quan » tinh quang, trinh luat, trinh han
hieu xanh » chieu xanh, hieu manh, hieu nganh
quan dung » quang dung, quan duong, qua dung
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
cong san » cong tac
than cap » khan cap, thanh lap, thanh cac
phan cau » phan dau, phan cac, phan tu

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 trinh quan dung cong san ((than cap) OR (phan cau))~.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - canh trinh quan dung cong san ((than cap) or (phan cau))*.