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
cong toan » cong tan, cong hoan, cong tuan
toan phan » thanh phan, toan ban, hoa phan
doanh va » doanh tai, doanh cua, hanh va

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((chieu sang) OR (hieu lang)) - chinh ((doanh va) or (doan va)) nhung cong toan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sang) OR (hieu lang)) - chinh ((doanh va) OR (doan va)) nhung cong toan phan tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chieu sang) OR (hieu lang)) - chinh ((doanh va) or (doan va)) nhung cong toan phan tu".
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sang) OR (hieu lang)) - chinh ((doanh va) or (doan va)) nhung cong toan phan tu*.