Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
nhung cong » dung cong, thong cong, hang cong
tranh ve » trinh ve, thanh ve, tranh va
ve nhung » va nhung, tu nhung
san toan » van toan, manh toan, xuan toan
dan toan » van toan, dan than, manh toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sang) or (chieu sach)) - canh tranh ve nhung cong ((san toan) or (dan toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (chieu sach)) - canh tranh ve nhung cong ((san toan) OR (dan toan)) cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (chieu sach)) - canh tranh ve nhung cong ((san toan) or (dan toan)) cao*.