Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
lanh tranh » lan tranh, hanh trinh, sach tranh
hieu xanh » chieu xanh, hieu manh, hieu nganh
cua thong » cua thuong, cua khong, cua tong
doc hieu » toc thieu, hoc thieu, hoc hien
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than ban » thanh ban, toan ban, than man

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - ((lanh tranh) OR (canh tranh)) cua thong cong dan than ban~".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - ((lanh tranh) OR (canh tranh)) cua thong cong dan than ban*.