Perhaps you should try some spelling variations:
vien nganh » vien thanh
canh thanh » canh tranh, danh thanh, anh thanh
hieu xanh » chieu xanh, hieu manh, hieu nganh
qua dung » quang dung, qua song, qua cong
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan ban » van 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 xanh) or (vien nganh)) - canh thanh ((qua dung) OR (su dung)) cong dan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu xanh) OR (vien nganh)) - canh thanh ((qua dung) OR (su dung)) cong dan toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu xanh) or (vien nganh)) - canh thanh ((qua dung) OR (su dung)) cong dan toan ban".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu xanh) or (vien nganh)) - canh thanh ((qua dung) OR (su dung)) cong dan toan ban*.