Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
manh trung » manh tung, thanh trung, manh hung
dung cong » dung trong
trung va » truong va, trang va, trung ha
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap
va dung » van dung, va duong, vat dung

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)) - manh trung va dung cong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (chieu sach)) - manh trung va dung cong dan toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (chieu sach)) - manh trung va dung cong dan toan cau*.