Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, nhieu tang
thong cong » trong cong, tong cong, thong thong
hieu lang » hieu quang, nhieu tang, hieu van
dang cong » dung cong
toan phan » thanh phan, toan ban, hoa phan
tranh va » tranh van, trang va, trinh va
phan cau » phan dau, phan cac, phan tu

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

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