Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, nhieu tang
nhung cong » dung cong, thong cong, hang cong
hieu lang » hieu quang, nhieu tang, hieu van
trung cap » truong cao, trung tam
trung ha » trung hoc, trung tam
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
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: nho ((chieu sang) OR (hieu lang)) - thanh ((trung ha) or (trung cap)) nhung cong bai toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: nho ((chieu sang) OR (hieu lang)) - thanh ((trung ha) OR (trung cap)) nhung cong bai toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "nho ((chieu sang) OR (hieu lang)) - thanh ((trung ha) or (trung cap)) nhung cong bai toan cao".
• Adding a wildcard symbol may retrieve word variants: nho ((chieu sang) OR (hieu lang)) - thanh ((trung ha) or (trung cap)) nhung cong bai toan cao*.