Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
cach bang » cach mang, cac bang, hoach bang
cong tan » cong tac, cong san, cong thanh
toan cao » toan ban
toan tap » toan ban
bang va » hang va, ban va, trang 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)) - cach bang va nhung cong tan ((toan cao) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sang) OR (hieu lang)) - cach bang va nhung cong tan ((toan cao) OR (toan tap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chieu sang) OR (hieu lang)) - cach bang va nhung cong tan ((toan cao) or (toan tap))".
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sang) OR (hieu lang)) - cach bang va nhung cong tan ((toan cao) or (toan tap))*.