Perhaps you should try some spelling variations:
nhung cong » thong cong, hang cong, nhung don
hieu xanh » chieu xanh, hieu manh, hieu nganh
tranh cua » doanh cua, manh cua
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
toan cau » toan ban, toan tap, toan tai
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 xanh - canh tranh cua ((nhung cong) or (dung cong)) dan ((toan cau) or (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - canh tranh cua ((nhung cong) OR (dung cong)) dan ((toan cau) OR (toan cao)).
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - canh tranh cua ((nhung cong) or (dung cong)) dan ((toan cau) or (toan cao))*.