Perhaps you should try some spelling variations:
tranh quang » tran quang, trinh quang, tinh quang
quang dung » quang trung, ung dung, cuong dung
cong thanh » dong thanh, cong trinh, cong tan
dung cong » dung trong
doc hieu » toc thieu, hoc thieu
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 quang dung cong thanh ((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 quang dung cong thanh ((than cap) OR (phan dau)).
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (hoc hien)) xanh - canh tranh quang dung cong thanh ((than cap) or (phan dau))*.