Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu tinh, hieu manh
chieu sang » chieu sach, hieu lang, nhieu tang
tran van » luan van
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan tap » toan ban
tra van » ta van, trang van, tranh van

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu xanh) OR (chieu sang)) - thanh ((tra van) OR (tran van)) trong cong dan toan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu xanh) OR (chieu sang)) - thanh ((tra van) or (tran van)) trong cong dan toan tap~".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu xanh) OR (chieu sang)) - thanh ((tra van) or (tran van)) trong cong dan toan tap*.