Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
dung cong » dung trong
cong dang » cong dong, cong dan, cong dung
tranh va » tranh van, trang va, trinh va
dang van » hoang van, hang va
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 (hieu lang)) - canh tranh va dung cong dang van ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) OR (hieu lang)) - canh tranh va dung cong dang van ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) OR (hieu lang)) - canh tranh va dung cong dang van ban*.