Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
thong cong » trong cong, tong cong, thong thong
hien xanh » hien hanh, hien nhanh, chieu xanh
tranh cua » doanh cua, manh cua
dung cong » dung trong
dan than » dan chan, ban than, van than
van toan » van tuan, van tan, van thanh

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien xanh - hanh tranh cua ((thong cong) or (dung cong)) ((dan than) or (van toan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - hanh tranh cua ((thong cong) OR (dung cong)) ((dan than) OR (van toan)) ban.
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - hanh tranh cua ((thong cong) or (dung cong)) ((dan than) or (van toan)) ban*.