Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hanh tranh » canh tranh, hanh trinh, hanh trang
hieu xanh » chieu xanh, hieu manh, hieu nganh
tranh cua » doanh cua, manh cua
cua thong » cua thuong, cua khong, cua tong
doc hieu » toc thieu, hoc thieu, hoc hien
tan toan » tap toan, van toan, dan toan

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 - hanh tranh cua thong cong ((tan toan) or (tan tran)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh tranh cua thong cong ((tan toan) OR (tan tran)) cao*.