Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
tranh cua » doanh cua, manh cua
phan cong » thanh cong
cua phan » cua nhan, cua phap, cua han
tap toan » tap doan, tap quan
bai toan » bai tap

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 (chieu sach)) - canh tranh cua phan cong ((tap toan) OR (bai toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (chieu sach)) - canh tranh cua phan cong ((tap toan) OR (bai toan)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (chieu sach)) - canh tranh cua phan cong ((tap toan) OR (bai toan)) cao".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (chieu sach)) - canh tranh cua phan cong ((tap toan) OR (bai toan)) cao*.