Perhaps you should try some spelling variations:
tranh chuan » trinh chuan, tranh chua, tranh cua
chuan nang » chua nang, chuan trang, chuc nang
nang cong » nang song, dang cong, bang cong
doc hieu » toc thieu, hoc thieu, hoc hien
ho chieu » theo chieu, hoc thieu, doi chieu
cong san » cong tac
than cau » phan cau, than cap, thanh chau
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc hieu) or (ho chieu)) xanh - canh tranh chuan nang cong san ((than cau) OR (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (ho chieu)) xanh - canh tranh chuan nang cong san ((than cau) OR (toan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (ho chieu)) xanh - canh tranh chuan nang cong san ((than cau) OR (toan cau))".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (ho chieu)) xanh - canh tranh chuan nang cong san ((than cau) OR (toan cau))*.