Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
hoc tang » hoc tan, hoc tieng, hoc trong
hoc bang » hoc bong, hoc dan, hoc bai
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu lang) OR (chieu sang)) - canh tranh ((hoc tang) or (hoc bang)) cong dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (chieu sang)) - canh tranh ((hoc tang) OR (hoc bang)) cong dan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) OR (chieu sang)) - canh tranh ((hoc tang) or (hoc bang)) cong dan than cau".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) OR (chieu sang)) - canh tranh ((hoc tang) or (hoc bang)) cong dan than cau*.