Perhaps you should try some spelling variations:
hanh trang » thanh trung, canh tranh, hanh trinh
chieu sang » chieu sach, chieu xanh, hieu lang
nhung cong » thong cong, hang cong, nhung don
hieu quan » hieu qua, lieu quan, thien quan
trang cua » tranh cua, tang cua, trung cua
dung cong » dung trong
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 trang cua ((nhung cong) OR (dung cong)) dan toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu quan)) - hanh trang cua ((nhung cong) OR (dung cong)) dan toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (hieu quan)) - hanh trang cua ((nhung cong) OR (dung cong)) dan toan tap".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu quan)) - hanh trang cua ((nhung cong) OR (dung cong)) dan toan tap*.