Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, hieu lang
hieu quan » hieu qua, lieu quan, thien quan
hanh tran » hanh trang, thanh tran, hanh tram
van nhung » van nhuong, van hung, van phung
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sang) or (hieu quan)) - hanh tran ((van nhung) OR (va nhung)) cong dan toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu quan)) - hanh tran ((van nhung) OR (va nhung)) cong dan toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (hieu quan)) - hanh tran ((van nhung) OR (va nhung)) cong dan toan tap".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu quan)) - hanh tran ((van nhung) OR (va nhung)) cong dan toan tap*.