Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
canh trinh » canh tranh, hanh trinh, canh tinh
nhung cong » thong cong, hang cong, nhung don
dung cong » dung trong
trinh va » trinh van, trinh vat, trinh ve
van toan » van tuan, van tan, van thanh
toan cau » toan cao, toan ban, toan 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 trinh va ((nhung cong) OR (dung cong)) van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (chieu sach)) - canh trinh va ((nhung cong) OR (dung cong)) van toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (chieu sach)) - canh trinh va ((nhung cong) OR (dung cong)) van toan cau".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (chieu sach)) - canh trinh va ((nhung cong) OR (dung cong)) van toan cau*.