Perhaps you should try some spelling variations:
tranh viet » tran viet, trinh viet, trang viet
cong thanh » dong thanh, cong trinh, cong tan
hoc thieu » toc thieu, hoc hien
viet dung » viet hung, viet huong, viet trung
dung cong » dung trong
doc hieu » toc thieu, hoc hien
san ban » sang ban, van ban, san van
can ban » van ban, toan ban

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 thieu)) tinh - canh tranh viet dung cong thanh ((san ban) or (can ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (hoc thieu)) tinh - canh tranh viet dung cong thanh ((san ban) OR (can ban)).
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (hoc thieu)) tinh - canh tranh viet dung cong thanh ((san ban) or (can ban))*.