Perhaps you should try some spelling variations:
tranh qua » tranh cua, thanh qua, trinh qua
dung cong » dung trong
doc hieu » toc thieu, hoc thieu
qua dung » quang dung, su dung, qua song
cong tan » cong tac, cong san, cong thanh
than cap » khan cap, thanh lap, thanh cac
phan dau » phan tu, hang dau

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 (hoc hien)) xanh - canh tranh qua dung cong tan ((than cap) or (phan dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (hoc hien)) xanh - canh tranh qua dung cong tan ((than cap) OR (phan dau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) OR (hoc hien)) xanh - canh tranh qua dung cong tan ((than cap) or (phan dau))".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) OR (hoc hien)) xanh - canh tranh qua dung cong tan ((than cap) or (phan dau))*.